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0efdf0fe | 1 | .. _bgp: |
42fc5d26 QY |
2 | |
3 | *** | |
4 | BGP | |
5 | *** | |
6 | ||
8fcedbd2 | 7 | :abbr:`BGP` stands for Border Gateway Protocol. The latest BGP version is 4. |
d1e7591e | 8 | BGP-4 is one of the Exterior Gateway Protocols and the de facto standard |
8fcedbd2 QY |
9 | interdomain routing protocol. BGP-4 is described in :rfc:`1771` and updated by |
10 | :rfc:`4271`. :rfc:`2858` adds multiprotocol support to BGP-4. | |
42fc5d26 | 11 | |
0efdf0fe | 12 | .. _starting-bgp: |
42fc5d26 QY |
13 | |
14 | Starting BGP | |
15 | ============ | |
16 | ||
8fcedbd2 QY |
17 | The default configuration file of *bgpd* is :file:`bgpd.conf`. *bgpd* searches |
18 | the current directory first, followed by |INSTALL_PREFIX_ETC|/bgpd.conf. All of | |
19 | *bgpd*'s commands must be configured in :file:`bgpd.conf` when the integrated | |
20 | config is not being used. | |
42fc5d26 | 21 | |
c1a54c05 | 22 | *bgpd* specific invocation options are described below. Common options may also |
0efdf0fe | 23 | be specified (:ref:`common-invocation-options`). |
42fc5d26 | 24 | |
c1a54c05 | 25 | .. program:: bgpd |
42fc5d26 | 26 | |
c9365894 | 27 | .. option:: -p, --bgp_port <port> |
42fc5d26 | 28 | |
db759bb0 | 29 | Set the bgp protocol's port number. When port number is 0, that means do not |
30 | listen bgp port. | |
42fc5d26 | 31 | |
c9365894 | 32 | .. option:: -l, --listenon |
42fc5d26 | 33 | |
c0868e8b QY |
34 | Specify a specific IP address for bgpd to listen on, rather than its default |
35 | of ``0.0.0.0`` / ``::``. This can be useful to constrain bgpd to an internal | |
36 | address, or to run multiple bgpd processes on one host. | |
42fc5d26 | 37 | |
c17537f9 MBG |
38 | Note that this option implies the --no_kernel option, and no learned routes will be installed into the linux kernel. |
39 | ||
11a9a236 DS |
40 | .. option:: -n, --no_kernel |
41 | ||
42 | Do not install learned routes into the linux kernel. This option is useful | |
43 | for a route-reflector environment or if you are running multiple bgp | |
44 | processes in the same namespace. This option is different than the --no_zebra | |
45 | option in that a ZAPI connection is made. | |
46 | ||
8dad2243 DS |
47 | This option can also be toggled during runtime by using the |
48 | ``[no] bgp no-rib`` commands in VTY shell. | |
49 | ||
50 | Note that this option will persist after saving the configuration during | |
51 | runtime, unless unset by the ``no bgp no-rib`` command in VTY shell prior to | |
52 | a configuration write operation. | |
53 | ||
11a9a236 DS |
54 | .. option:: -S, --skip_runas |
55 | ||
56 | Skip the normal process of checking capabilities and changing user and group | |
57 | information. | |
58 | ||
59 | .. option:: -e, --ecmp | |
60 | ||
61 | Run BGP with a limited ecmp capability, that is different than what BGP | |
62 | was compiled with. The value specified must be greater than 0 and less | |
63 | than or equal to the MULTIPATH_NUM specified on compilation. | |
64 | ||
65 | .. option:: -Z, --no_zebra | |
66 | ||
67 | Do not communicate with zebra at all. This is different than the --no_kernel | |
68 | option in that we do not even open a ZAPI connection to the zebra process. | |
69 | ||
70 | .. option:: -s, --socket_size | |
71 | ||
72 | When opening tcp connections to our peers, set the socket send buffer | |
73 | size that the kernel will use for the peers socket. This option | |
74 | is only really useful at a very large scale. Experimentation should | |
75 | be done to see if this is helping or not at the scale you are running | |
76 | at. | |
77 | ||
78 | LABEL MANAGER | |
79 | ------------- | |
80 | ||
81 | .. option:: -I, --int_num | |
82 | ||
83 | Set zclient id. This is required when using Zebra label manager in proxy mode. | |
84 | ||
8fcedbd2 | 85 | .. _bgp-basic-concepts: |
42fc5d26 | 86 | |
8fcedbd2 QY |
87 | Basic Concepts |
88 | ============== | |
42fc5d26 | 89 | |
8fcedbd2 | 90 | .. _bgp-autonomous-systems: |
c3c5a71f | 91 | |
8fcedbd2 QY |
92 | Autonomous Systems |
93 | ------------------ | |
42fc5d26 | 94 | |
c0868e8b QY |
95 | From :rfc:`1930`: |
96 | ||
97 | An AS is a connected group of one or more IP prefixes run by one or more | |
98 | network operators which has a SINGLE and CLEARLY DEFINED routing policy. | |
99 | ||
100 | Each AS has an identifying number associated with it called an :abbr:`ASN | |
101 | (Autonomous System Number)`. This is a two octet value ranging in value from 1 | |
102 | to 65535. The AS numbers 64512 through 65535 are defined as private AS numbers. | |
103 | Private AS numbers must not be advertised on the global Internet. | |
104 | ||
105 | The :abbr:`ASN (Autonomous System Number)` is one of the essential elements of | |
8fcedbd2 | 106 | BGP. BGP is a distance vector routing protocol, and the AS-Path framework |
c0868e8b | 107 | provides distance vector metric and loop detection to BGP. |
42fc5d26 | 108 | |
c0868e8b | 109 | .. seealso:: :rfc:`1930` |
42fc5d26 | 110 | |
8fcedbd2 | 111 | .. _bgp-address-families: |
42fc5d26 | 112 | |
8fcedbd2 QY |
113 | Address Families |
114 | ---------------- | |
42fc5d26 | 115 | |
c0868e8b QY |
116 | Multiprotocol extensions enable BGP to carry routing information for multiple |
117 | network layer protocols. BGP supports an Address Family Identifier (AFI) for | |
118 | IPv4 and IPv6. Support is also provided for multiple sets of per-AFI | |
119 | information via the BGP Subsequent Address Family Identifier (SAFI). FRR | |
120 | supports SAFIs for unicast information, labeled information (:rfc:`3107` and | |
121 | :rfc:`8277`), and Layer 3 VPN information (:rfc:`4364` and :rfc:`4659`). | |
c3c5a71f | 122 | |
8fcedbd2 | 123 | .. _bgp-route-selection: |
42fc5d26 | 124 | |
8fcedbd2 QY |
125 | Route Selection |
126 | --------------- | |
42fc5d26 | 127 | |
8fcedbd2 QY |
128 | The route selection process used by FRR's BGP implementation uses the following |
129 | decision criterion, starting at the top of the list and going towards the | |
130 | bottom until one of the factors can be used. | |
42fc5d26 | 131 | |
8fcedbd2 | 132 | 1. **Weight check** |
42fc5d26 | 133 | |
c1a54c05 | 134 | Prefer higher local weight routes to lower routes. |
42fc5d26 | 135 | |
8fcedbd2 QY |
136 | 2. **Local preference check** |
137 | ||
c1a54c05 | 138 | Prefer higher local preference routes to lower. |
42fc5d26 | 139 | |
8fcedbd2 QY |
140 | 3. **Local route check** |
141 | ||
c1a54c05 | 142 | Prefer local routes (statics, aggregates, redistributed) to received routes. |
42fc5d26 | 143 | |
8fcedbd2 QY |
144 | 4. **AS path length check** |
145 | ||
c1a54c05 | 146 | Prefer shortest hop-count AS_PATHs. |
42fc5d26 | 147 | |
8fcedbd2 QY |
148 | 5. **Origin check** |
149 | ||
c1a54c05 QY |
150 | Prefer the lowest origin type route. That is, prefer IGP origin routes to |
151 | EGP, to Incomplete routes. | |
42fc5d26 | 152 | |
8fcedbd2 QY |
153 | 6. **MED check** |
154 | ||
c1a54c05 | 155 | Where routes with a MED were received from the same AS, prefer the route |
0efdf0fe | 156 | with the lowest MED. :ref:`bgp-med`. |
42fc5d26 | 157 | |
8fcedbd2 QY |
158 | 7. **External check** |
159 | ||
c1a54c05 QY |
160 | Prefer the route received from an external, eBGP peer over routes received |
161 | from other types of peers. | |
42fc5d26 | 162 | |
8fcedbd2 QY |
163 | 8. **IGP cost check** |
164 | ||
c1a54c05 | 165 | Prefer the route with the lower IGP cost. |
42fc5d26 | 166 | |
8fcedbd2 QY |
167 | 9. **Multi-path check** |
168 | ||
c1a54c05 QY |
169 | If multi-pathing is enabled, then check whether the routes not yet |
170 | distinguished in preference may be considered equal. If | |
9e146a81 | 171 | :clicmd:`bgp bestpath as-path multipath-relax` is set, all such routes are |
c1a54c05 QY |
172 | considered equal, otherwise routes received via iBGP with identical AS_PATHs |
173 | or routes received from eBGP neighbours in the same AS are considered equal. | |
42fc5d26 | 174 | |
8fcedbd2 QY |
175 | 10. **Already-selected external check** |
176 | ||
07738543 QY |
177 | Where both routes were received from eBGP peers, then prefer the route |
178 | which is already selected. Note that this check is not applied if | |
179 | :clicmd:`bgp bestpath compare-routerid` is configured. This check can | |
180 | prevent some cases of oscillation. | |
181 | ||
8fcedbd2 QY |
182 | 11. **Router-ID check** |
183 | ||
07738543 QY |
184 | Prefer the route with the lowest `router-ID`. If the route has an |
185 | `ORIGINATOR_ID` attribute, through iBGP reflection, then that router ID is | |
186 | used, otherwise the `router-ID` of the peer the route was received from is | |
187 | used. | |
188 | ||
8fcedbd2 QY |
189 | 12. **Cluster-List length check** |
190 | ||
07738543 QY |
191 | The route with the shortest cluster-list length is used. The cluster-list |
192 | reflects the iBGP reflection path the route has taken. | |
193 | ||
8fcedbd2 QY |
194 | 13. **Peer address** |
195 | ||
07738543 QY |
196 | Prefer the route received from the peer with the higher transport layer |
197 | address, as a last-resort tie-breaker. | |
42fc5d26 | 198 | |
8fcedbd2 QY |
199 | .. _bgp-capability-negotiation: |
200 | ||
201 | Capability Negotiation | |
202 | ---------------------- | |
203 | ||
204 | When adding IPv6 routing information exchange feature to BGP. There were some | |
205 | proposals. :abbr:`IETF (Internet Engineering Task Force)` | |
206 | :abbr:`IDR (Inter Domain Routing)` adopted a proposal called Multiprotocol | |
207 | Extension for BGP. The specification is described in :rfc:`2283`. The protocol | |
208 | does not define new protocols. It defines new attributes to existing BGP. When | |
209 | it is used exchanging IPv6 routing information it is called BGP-4+. When it is | |
210 | used for exchanging multicast routing information it is called MBGP. | |
211 | ||
212 | *bgpd* supports Multiprotocol Extension for BGP. So if a remote peer supports | |
213 | the protocol, *bgpd* can exchange IPv6 and/or multicast routing information. | |
214 | ||
215 | Traditional BGP did not have the feature to detect a remote peer's | |
216 | capabilities, e.g. whether it can handle prefix types other than IPv4 unicast | |
217 | routes. This was a big problem using Multiprotocol Extension for BGP in an | |
218 | operational network. :rfc:`2842` adopted a feature called Capability | |
219 | Negotiation. *bgpd* use this Capability Negotiation to detect the remote peer's | |
220 | capabilities. If a peer is only configured as an IPv4 unicast neighbor, *bgpd* | |
221 | does not send these Capability Negotiation packets (at least not unless other | |
222 | optional BGP features require capability negotiation). | |
223 | ||
224 | By default, FRR will bring up peering with minimal common capability for the | |
225 | both sides. For example, if the local router has unicast and multicast | |
226 | capabilities and the remote router only has unicast capability the local router | |
227 | will establish the connection with unicast only capability. When there are no | |
228 | common capabilities, FRR sends Unsupported Capability error and then resets the | |
229 | connection. | |
230 | ||
8fcedbd2 QY |
231 | .. _bgp-router-configuration: |
232 | ||
233 | BGP Router Configuration | |
234 | ======================== | |
235 | ||
236 | ASN and Router ID | |
237 | ----------------- | |
238 | ||
239 | First of all you must configure BGP router with the :clicmd:`router bgp ASN` | |
240 | command. The AS number is an identifier for the autonomous system. The BGP | |
241 | protocol uses the AS number for detecting whether the BGP connection is | |
242 | internal or external. | |
243 | ||
244 | .. index:: router bgp ASN | |
245 | .. clicmd:: router bgp ASN | |
246 | ||
247 | Enable a BGP protocol process with the specified ASN. After | |
248 | this statement you can input any `BGP Commands`. | |
249 | ||
3d13052d | 250 | .. index:: router bgp ASN |
8fcedbd2 QY |
251 | .. clicmd:: no router bgp ASN |
252 | ||
253 | Destroy a BGP protocol process with the specified ASN. | |
254 | ||
255 | .. index:: bgp router-id A.B.C.D | |
256 | .. clicmd:: bgp router-id A.B.C.D | |
257 | ||
258 | This command specifies the router-ID. If *bgpd* connects to *zebra* it gets | |
259 | interface and address information. In that case default router ID value is | |
260 | selected as the largest IP Address of the interfaces. When `router zebra` is | |
261 | not enabled *bgpd* can't get interface information so `router-id` is set to | |
262 | 0.0.0.0. So please set router-id by hand. | |
263 | ||
c8a5e5e1 QY |
264 | |
265 | .. _bgp-multiple-autonomous-systems: | |
266 | ||
267 | Multiple Autonomous Systems | |
268 | --------------------------- | |
269 | ||
270 | FRR's BGP implementation is capable of running multiple autonomous systems at | |
271 | once. Each configured AS corresponds to a :ref:`zebra-vrf`. In the past, to get | |
272 | the same functionality the network administrator had to run a new *bgpd* | |
273 | process; using VRFs allows multiple autonomous systems to be handled in a | |
274 | single process. | |
275 | ||
276 | When using multiple autonomous systems, all router config blocks after the | |
277 | first one must specify a VRF to be the target of BGP's route selection. This | |
278 | VRF must be unique within respect to all other VRFs being used for the same | |
279 | purpose, i.e. two different autonomous systems cannot use the same VRF. | |
280 | However, the same AS can be used with different VRFs. | |
281 | ||
282 | .. note:: | |
283 | ||
284 | The separated nature of VRFs makes it possible to peer a single *bgpd* | |
edde3ce9 QY |
285 | process to itself, on one machine. Note that this can be done fully within |
286 | BGP without a corresponding VRF in the kernel or Zebra, which enables some | |
287 | practical use cases such as :ref:`route reflectors <bgp-route-reflector>` | |
288 | and route servers. | |
c8a5e5e1 QY |
289 | |
290 | Configuration of additional autonomous systems, or of a router that targets a | |
291 | specific VRF, is accomplished with the following command: | |
292 | ||
293 | .. index:: router bgp ASN vrf VRFNAME | |
294 | .. clicmd:: router bgp ASN vrf VRFNAME | |
295 | ||
296 | ``VRFNAME`` is matched against VRFs configured in the kernel. When ``vrf | |
297 | VRFNAME`` is not specified, the BGP protocol process belongs to the default | |
298 | VRF. | |
299 | ||
300 | An example configuration with multiple autonomous systems might look like this: | |
301 | ||
302 | .. code-block:: frr | |
303 | ||
304 | router bgp 1 | |
305 | neighbor 10.0.0.1 remote-as 20 | |
306 | neighbor 10.0.0.2 remote-as 30 | |
307 | ! | |
308 | router bgp 2 vrf blue | |
309 | neighbor 10.0.0.3 remote-as 40 | |
310 | neighbor 10.0.0.4 remote-as 50 | |
311 | ! | |
312 | router bgp 3 vrf red | |
313 | neighbor 10.0.0.5 remote-as 60 | |
314 | neighbor 10.0.0.6 remote-as 70 | |
315 | ... | |
316 | ||
c8a5e5e1 QY |
317 | .. seealso:: :ref:`bgp-vrf-route-leaking` |
318 | .. seealso:: :ref:`zebra-vrf` | |
319 | ||
320 | ||
321 | .. _bgp-views: | |
322 | ||
323 | Views | |
324 | ----- | |
325 | ||
326 | In addition to supporting multiple autonomous systems, FRR's BGP implementation | |
327 | also supports *views*. | |
328 | ||
329 | BGP views are almost the same as normal BGP processes, except that routes | |
195c7461 QY |
330 | selected by BGP are not installed into the kernel routing table. Each BGP view |
331 | provides an independent set of routing information which is only distributed | |
332 | via BGP. Multiple views can be supported, and BGP view information is always | |
333 | independent from other routing protocols and Zebra/kernel routes. BGP views use | |
334 | the core instance (i.e., default VRF) for communication with peers. | |
edde3ce9 | 335 | |
c8a5e5e1 QY |
336 | .. index:: router bgp AS-NUMBER view NAME |
337 | .. clicmd:: router bgp AS-NUMBER view NAME | |
338 | ||
339 | Make a new BGP view. You can use an arbitrary word for the ``NAME``. Routes | |
340 | selected by the view are not installed into the kernel routing table. | |
341 | ||
342 | With this command, you can setup Route Server like below. | |
343 | ||
344 | .. code-block:: frr | |
345 | ||
346 | ! | |
347 | router bgp 1 view 1 | |
348 | neighbor 10.0.0.1 remote-as 2 | |
349 | neighbor 10.0.0.2 remote-as 3 | |
350 | ! | |
351 | router bgp 2 view 2 | |
352 | neighbor 10.0.0.3 remote-as 4 | |
353 | neighbor 10.0.0.4 remote-as 5 | |
354 | ||
355 | .. index:: show [ip] bgp view NAME | |
356 | .. clicmd:: show [ip] bgp view NAME | |
357 | ||
358 | Display the routing table of BGP view ``NAME``. | |
359 | ||
360 | ||
8fcedbd2 QY |
361 | Route Selection |
362 | --------------- | |
c3c5a71f | 363 | |
c1a54c05 | 364 | .. index:: bgp bestpath as-path confed |
29adcd50 | 365 | .. clicmd:: bgp bestpath as-path confed |
42fc5d26 | 366 | |
c1a54c05 QY |
367 | This command specifies that the length of confederation path sets and |
368 | sequences should should be taken into account during the BGP best path | |
369 | decision process. | |
42fc5d26 | 370 | |
c3c5a71f | 371 | .. index:: bgp bestpath as-path multipath-relax |
29adcd50 | 372 | .. clicmd:: bgp bestpath as-path multipath-relax |
42fc5d26 | 373 | |
c1a54c05 QY |
374 | This command specifies that BGP decision process should consider paths |
375 | of equal AS_PATH length candidates for multipath computation. Without | |
376 | the knob, the entire AS_PATH must match for multipath computation. | |
c3c5a71f | 377 | |
29adcd50 | 378 | .. clicmd:: bgp bestpath compare-routerid |
42fc5d26 | 379 | |
c1a54c05 QY |
380 | Ensure that when comparing routes where both are equal on most metrics, |
381 | including local-pref, AS_PATH length, IGP cost, MED, that the tie is broken | |
382 | based on router-ID. | |
42fc5d26 | 383 | |
c1a54c05 QY |
384 | If this option is enabled, then the already-selected check, where |
385 | already selected eBGP routes are preferred, is skipped. | |
42fc5d26 | 386 | |
c1a54c05 QY |
387 | If a route has an `ORIGINATOR_ID` attribute because it has been reflected, |
388 | that `ORIGINATOR_ID` will be used. Otherwise, the router-ID of the peer the | |
389 | route was received from will be used. | |
42fc5d26 | 390 | |
c1a54c05 QY |
391 | The advantage of this is that the route-selection (at this point) will be |
392 | more deterministic. The disadvantage is that a few or even one lowest-ID | |
d1e7591e | 393 | router may attract all traffic to otherwise-equal paths because of this |
c1a54c05 QY |
394 | check. It may increase the possibility of MED or IGP oscillation, unless |
395 | other measures were taken to avoid these. The exact behaviour will be | |
396 | sensitive to the iBGP and reflection topology. | |
42fc5d26 | 397 | |
8fcedbd2 QY |
398 | .. _bgp-distance: |
399 | ||
400 | Administrative Distance Metrics | |
401 | ------------------------------- | |
402 | ||
403 | .. index:: distance bgp (1-255) (1-255) (1-255) | |
404 | .. clicmd:: distance bgp (1-255) (1-255) (1-255) | |
405 | ||
406 | This command change distance value of BGP. The arguments are the distance | |
407 | values for for external routes, internal routes and local routes | |
408 | respectively. | |
409 | ||
410 | .. index:: distance (1-255) A.B.C.D/M | |
411 | .. clicmd:: distance (1-255) A.B.C.D/M | |
412 | ||
413 | .. index:: distance (1-255) A.B.C.D/M WORD | |
414 | .. clicmd:: distance (1-255) A.B.C.D/M WORD | |
415 | ||
416 | Sets the administrative distance for a particular route. | |
42fc5d26 | 417 | |
713c64dd DA |
418 | .. _bgp-requires-policy: |
419 | ||
420 | Require policy on EBGP | |
421 | ------------------------------- | |
422 | ||
3d13052d | 423 | .. index:: bgp ebgp-requires-policy |
713c64dd DA |
424 | .. clicmd:: [no] bgp ebgp-requires-policy |
425 | ||
8955d9e5 DA |
426 | This command requires incoming and outgoing filters to be applied |
427 | for eBGP sessions. Without the incoming filter, no routes will be | |
428 | accepted. Without the outgoing filter, no routes will be announced. | |
429 | ||
430 | This is enabled by default. | |
713c64dd | 431 | |
62c42b0e DA |
432 | When the incoming or outgoing filter is missing you will see |
433 | "(Policy)" sign under ``show bgp summary``: | |
434 | ||
435 | .. code-block:: frr | |
436 | ||
437 | exit1# show bgp summary | |
438 | ||
439 | IPv4 Unicast Summary: | |
440 | BGP router identifier 10.10.10.1, local AS number 65001 vrf-id 0 | |
441 | BGP table version 4 | |
442 | RIB entries 7, using 1344 bytes of memory | |
443 | Peers 2, using 43 KiB of memory | |
444 | ||
445 | Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd PfxSnt | |
446 | 192.168.0.2 4 65002 8 10 0 0 0 00:03:09 5 (Policy) | |
447 | fe80:1::2222 4 65002 9 11 0 0 0 00:03:09 (Policy) (Policy) | |
448 | ||
f0c81afe | 449 | Reject routes with AS_SET or AS_CONFED_SET types |
5031d886 | 450 | ------------------------------------------------ |
f0c81afe | 451 | |
3d13052d | 452 | .. index:: bgp reject-as-sets |
f0c81afe DA |
453 | .. clicmd:: [no] bgp reject-as-sets |
454 | ||
455 | This command enables rejection of incoming and outgoing routes having AS_SET or AS_CONFED_SET type. | |
456 | ||
835e9c5d DA |
457 | Disable checking if nexthop is connected on EBGP sessions |
458 | --------------------------------------------------------- | |
459 | ||
3d13052d | 460 | .. index:: bgp disable-ebgp-connected-route-check |
835e9c5d DA |
461 | .. clicmd:: [no] bgp disable-ebgp-connected-route-check |
462 | ||
463 | This command is used to disable the connection verification process for EBGP peering sessions | |
464 | that are reachable by a single hop but are configured on a loopback interface or otherwise | |
465 | configured with a non-directly connected IP address. | |
466 | ||
0efdf0fe | 467 | .. _bgp-route-flap-dampening: |
42fc5d26 | 468 | |
8fcedbd2 QY |
469 | Route Flap Dampening |
470 | -------------------- | |
42fc5d26 | 471 | |
c1a54c05 QY |
472 | .. clicmd:: bgp dampening (1-45) (1-20000) (1-20000) (1-255) |
473 | ||
c1a54c05 | 474 | This command enables BGP route-flap dampening and specifies dampening parameters. |
42fc5d26 | 475 | |
c1a54c05 QY |
476 | half-life |
477 | Half-life time for the penalty | |
42fc5d26 | 478 | |
c1a54c05 QY |
479 | reuse-threshold |
480 | Value to start reusing a route | |
42fc5d26 | 481 | |
c1a54c05 QY |
482 | suppress-threshold |
483 | Value to start suppressing a route | |
42fc5d26 | 484 | |
c1a54c05 QY |
485 | max-suppress |
486 | Maximum duration to suppress a stable route | |
42fc5d26 | 487 | |
c1a54c05 QY |
488 | The route-flap damping algorithm is compatible with :rfc:`2439`. The use of |
489 | this command is not recommended nowadays. | |
42fc5d26 | 490 | |
319a7d06 DA |
491 | At the moment, route-flap dampening is not working per VRF and is working only |
492 | for IPv4 unicast and multicast. | |
493 | ||
c1a54c05 | 494 | .. seealso:: |
8fcedbd2 | 495 | https://www.ripe.net/publications/docs/ripe-378 |
42fc5d26 | 496 | |
0efdf0fe | 497 | .. _bgp-med: |
42fc5d26 | 498 | |
8fcedbd2 QY |
499 | Multi-Exit Discriminator |
500 | ------------------------ | |
42fc5d26 | 501 | |
8fcedbd2 | 502 | The BGP :abbr:`MED (Multi-Exit Discriminator)` attribute has properties which |
c1a54c05 QY |
503 | can cause subtle convergence problems in BGP. These properties and problems |
504 | have proven to be hard to understand, at least historically, and may still not | |
505 | be widely understood. The following attempts to collect together and present | |
506 | what is known about MED, to help operators and FRR users in designing and | |
507 | configuring their networks. | |
42fc5d26 | 508 | |
07a17e6d QY |
509 | The BGP :abbr:`MED` attribute is intended to allow one AS to indicate its |
510 | preferences for its ingress points to another AS. The MED attribute will not be | |
511 | propagated on to another AS by the receiving AS - it is 'non-transitive' in the | |
512 | BGP sense. | |
42fc5d26 | 513 | |
c1a54c05 QY |
514 | E.g., if AS X and AS Y have 2 different BGP peering points, then AS X might set |
515 | a MED of 100 on routes advertised at one and a MED of 200 at the other. When AS | |
516 | Y selects between otherwise equal routes to or via AS X, AS Y should prefer to | |
517 | take the path via the lower MED peering of 100 with AS X. Setting the MED | |
518 | allows an AS to influence the routing taken to it within another, neighbouring | |
519 | AS. | |
42fc5d26 QY |
520 | |
521 | In this use of MED it is not really meaningful to compare the MED value on | |
c1a54c05 QY |
522 | routes where the next AS on the paths differs. E.g., if AS Y also had a route |
523 | for some destination via AS Z in addition to the routes from AS X, and AS Z had | |
524 | also set a MED, it wouldn't make sense for AS Y to compare AS Z's MED values to | |
525 | those of AS X. The MED values have been set by different administrators, with | |
526 | different frames of reference. | |
42fc5d26 QY |
527 | |
528 | The default behaviour of BGP therefore is to not compare MED values across | |
dc1046f7 | 529 | routes received from different neighbouring ASes. In FRR this is done by |
c1a54c05 QY |
530 | comparing the neighbouring, left-most AS in the received AS_PATHs of the routes |
531 | and only comparing MED if those are the same. | |
532 | ||
533 | Unfortunately, this behaviour of MED, of sometimes being compared across routes | |
534 | and sometimes not, depending on the properties of those other routes, means MED | |
535 | can cause the order of preference over all the routes to be undefined. That is, | |
536 | given routes A, B, and C, if A is preferred to B, and B is preferred to C, then | |
537 | a well-defined order should mean the preference is transitive (in the sense of | |
013f9762 | 538 | orders [#med-transitivity-rant]_) and that A would be preferred to C. |
42fc5d26 | 539 | |
c3c5a71f QY |
540 | However, when MED is involved this need not be the case. With MED it is |
541 | possible that C is actually preferred over A. So A is preferred to B, B is | |
542 | preferred to C, but C is preferred to A. This can be true even where BGP | |
c1a54c05 QY |
543 | defines a deterministic 'most preferred' route out of the full set of A,B,C. |
544 | With MED, for any given set of routes there may be a deterministically | |
545 | preferred route, but there need not be any way to arrange them into any order | |
546 | of preference. With unmodified MED, the order of preference of routes literally | |
547 | becomes undefined. | |
42fc5d26 | 548 | |
c3c5a71f | 549 | That MED can induce non-transitive preferences over routes can cause issues. |
c1a54c05 QY |
550 | Firstly, it may be perceived to cause routing table churn locally at speakers; |
551 | secondly, and more seriously, it may cause routing instability in iBGP | |
552 | topologies, where sets of speakers continually oscillate between different | |
553 | paths. | |
42fc5d26 | 554 | |
c3c5a71f | 555 | The first issue arises from how speakers often implement routing decisions. |
c1a54c05 QY |
556 | Though BGP defines a selection process that will deterministically select the |
557 | same route as best at any given speaker, even with MED, that process requires | |
558 | evaluating all routes together. For performance and ease of implementation | |
559 | reasons, many implementations evaluate route preferences in a pair-wise fashion | |
560 | instead. Given there is no well-defined order when MED is involved, the best | |
561 | route that will be chosen becomes subject to implementation details, such as | |
562 | the order the routes are stored in. That may be (locally) non-deterministic, | |
563 | e.g.: it may be the order the routes were received in. | |
42fc5d26 QY |
564 | |
565 | This indeterminism may be considered undesirable, though it need not cause | |
c1a54c05 QY |
566 | problems. It may mean additional routing churn is perceived, as sometimes more |
567 | updates may be produced than at other times in reaction to some event . | |
42fc5d26 QY |
568 | |
569 | This first issue can be fixed with a more deterministic route selection that | |
c3c5a71f | 570 | ensures routes are ordered by the neighbouring AS during selection. |
9e146a81 | 571 | :clicmd:`bgp deterministic-med`. This may reduce the number of updates as routes |
c1a54c05 QY |
572 | are received, and may in some cases reduce routing churn. Though, it could |
573 | equally deterministically produce the largest possible set of updates in | |
574 | response to the most common sequence of received updates. | |
42fc5d26 QY |
575 | |
576 | A deterministic order of evaluation tends to imply an additional overhead of | |
c3c5a71f | 577 | sorting over any set of n routes to a destination. The implementation of |
dc1046f7 | 578 | deterministic MED in FRR scales significantly worse than most sorting |
c1a54c05 QY |
579 | algorithms at present, with the number of paths to a given destination. That |
580 | number is often low enough to not cause any issues, but where there are many | |
581 | paths, the deterministic comparison may quickly become increasingly expensive | |
582 | in terms of CPU. | |
583 | ||
584 | Deterministic local evaluation can *not* fix the second, more major, issue of | |
585 | MED however. Which is that the non-transitive preference of routes MED can | |
586 | cause may lead to routing instability or oscillation across multiple speakers | |
587 | in iBGP topologies. This can occur with full-mesh iBGP, but is particularly | |
588 | problematic in non-full-mesh iBGP topologies that further reduce the routing | |
589 | information known to each speaker. This has primarily been documented with iBGP | |
749afd7d RF |
590 | :ref:`route-reflection <bgp-route-reflector>` topologies. However, any |
591 | route-hiding technologies potentially could also exacerbate oscillation with MED. | |
c1a54c05 QY |
592 | |
593 | This second issue occurs where speakers each have only a subset of routes, and | |
594 | there are cycles in the preferences between different combinations of routes - | |
595 | as the undefined order of preference of MED allows - and the routes are | |
596 | distributed in a way that causes the BGP speakers to 'chase' those cycles. This | |
597 | can occur even if all speakers use a deterministic order of evaluation in route | |
598 | selection. | |
599 | ||
600 | E.g., speaker 4 in AS A might receive a route from speaker 2 in AS X, and from | |
601 | speaker 3 in AS Y; while speaker 5 in AS A might receive that route from | |
602 | speaker 1 in AS Y. AS Y might set a MED of 200 at speaker 1, and 100 at speaker | |
603 | 3. I.e, using ASN:ID:MED to label the speakers: | |
42fc5d26 QY |
604 | |
605 | :: | |
606 | ||
c1a54c05 QY |
607 | . |
608 | /---------------\\ | |
42fc5d26 | 609 | X:2------|--A:4-------A:5--|-Y:1:200 |
c1a54c05 QY |
610 | Y:3:100--|-/ | |
611 | \\---------------/ | |
c3c5a71f | 612 | |
42fc5d26 | 613 | |
42fc5d26 | 614 | |
c1a54c05 QY |
615 | Assuming all other metrics are equal (AS_PATH, ORIGIN, 0 IGP costs), then based |
616 | on the RFC4271 decision process speaker 4 will choose X:2 over Y:3:100, based | |
617 | on the lower ID of 2. Speaker 4 advertises X:2 to speaker 5. Speaker 5 will | |
618 | continue to prefer Y:1:200 based on the ID, and advertise this to speaker 4. | |
619 | Speaker 4 will now have the full set of routes, and the Y:1:200 it receives | |
620 | from 5 will beat X:2, but when speaker 4 compares Y:1:200 to Y:3:100 the MED | |
621 | check now becomes active as the ASes match, and now Y:3:100 is preferred. | |
622 | Speaker 4 therefore now advertises Y:3:100 to 5, which will also agrees that | |
623 | Y:3:100 is preferred to Y:1:200, and so withdraws the latter route from 4. | |
624 | Speaker 4 now has only X:2 and Y:3:100, and X:2 beats Y:3:100, and so speaker 4 | |
625 | implicitly updates its route to speaker 5 to X:2. Speaker 5 sees that Y:1:200 | |
626 | beats X:2 based on the ID, and advertises Y:1:200 to speaker 4, and the cycle | |
627 | continues. | |
42fc5d26 QY |
628 | |
629 | The root cause is the lack of a clear order of preference caused by how MED | |
630 | sometimes is and sometimes is not compared, leading to this cycle in the | |
631 | preferences between the routes: | |
632 | ||
633 | :: | |
634 | ||
c1a54c05 QY |
635 | . |
636 | /---> X:2 ---beats---> Y:3:100 --\\ | |
637 | | | | |
638 | | | | |
639 | \\---beats--- Y:1:200 <---beats---/ | |
c3c5a71f | 640 | |
42fc5d26 | 641 | |
42fc5d26 QY |
642 | |
643 | This particular type of oscillation in full-mesh iBGP topologies can be | |
644 | avoided by speakers preferring already selected, external routes rather than | |
c1a54c05 QY |
645 | choosing to update to new a route based on a post-MED metric (e.g. router-ID), |
646 | at the cost of a non-deterministic selection process. FRR implements this, as | |
647 | do many other implementations, so long as it is not overridden by setting | |
9e146a81 | 648 | :clicmd:`bgp bestpath compare-routerid`, and see also |
8fcedbd2 | 649 | :ref:`bgp-route-selection`. |
42fc5d26 QY |
650 | |
651 | However, more complex and insidious cycles of oscillation are possible with | |
c3c5a71f | 652 | iBGP route-reflection, which are not so easily avoided. These have been |
c1a54c05 QY |
653 | documented in various places. See, e.g.: |
654 | ||
655 | - [bgp-route-osci-cond]_ | |
656 | - [stable-flexible-ibgp]_ | |
657 | - [ibgp-correctness]_ | |
658 | ||
659 | for concrete examples and further references. | |
660 | ||
661 | There is as of this writing *no* known way to use MED for its original purpose; | |
662 | *and* reduce routing information in iBGP topologies; *and* be sure to avoid the | |
663 | instability problems of MED due the non-transitive routing preferences it can | |
664 | induce; in general on arbitrary networks. | |
665 | ||
666 | There may be iBGP topology specific ways to reduce the instability risks, even | |
667 | while using MED, e.g.: by constraining the reflection topology and by tuning | |
013f9762 | 668 | IGP costs between route-reflector clusters, see :rfc:`3345` for details. In the |
c1a54c05 QY |
669 | near future, the Add-Path extension to BGP may also solve MED oscillation while |
670 | still allowing MED to be used as intended, by distributing "best-paths per | |
671 | neighbour AS". This would be at the cost of distributing at least as many | |
672 | routes to all speakers as a full-mesh iBGP would, if not more, while also | |
673 | imposing similar CPU overheads as the "Deterministic MED" feature at each | |
674 | Add-Path reflector. | |
42fc5d26 QY |
675 | |
676 | More generally, the instability problems that MED can introduce on more | |
677 | complex, non-full-mesh, iBGP topologies may be avoided either by: | |
678 | ||
013f9762 | 679 | - Setting :clicmd:`bgp always-compare-med`, however this allows MED to be compared |
42fc5d26 QY |
680 | across values set by different neighbour ASes, which may not produce |
681 | coherent desirable results, of itself. | |
4b44467c | 682 | - Effectively ignoring MED by setting MED to the same value (e.g.: 0) using |
013f9762 QY |
683 | :clicmd:`set metric METRIC` on all received routes, in combination with |
684 | setting :clicmd:`bgp always-compare-med` on all speakers. This is the simplest | |
42fc5d26 QY |
685 | and most performant way to avoid MED oscillation issues, where an AS is happy |
686 | not to allow neighbours to inject this problematic metric. | |
687 | ||
42fc5d26 QY |
688 | As MED is evaluated after the AS_PATH length check, another possible use for |
689 | MED is for intra-AS steering of routes with equal AS_PATH length, as an | |
c1a54c05 QY |
690 | extension of the last case above. As MED is evaluated before IGP metric, this |
691 | can allow cold-potato routing to be implemented to send traffic to preferred | |
692 | hand-offs with neighbours, rather than the closest hand-off according to the | |
693 | IGP metric. | |
694 | ||
695 | Note that even if action is taken to address the MED non-transitivity issues, | |
696 | other oscillations may still be possible. E.g., on IGP cost if iBGP and IGP | |
697 | topologies are at cross-purposes with each other - see the Flavel and Roughan | |
698 | paper above for an example. Hence the guideline that the iBGP topology should | |
699 | follow the IGP topology. | |
700 | ||
c3c5a71f | 701 | .. index:: bgp deterministic-med |
29adcd50 | 702 | .. clicmd:: bgp deterministic-med |
42fc5d26 | 703 | |
c1a54c05 QY |
704 | Carry out route-selection in way that produces deterministic answers |
705 | locally, even in the face of MED and the lack of a well-defined order of | |
706 | preference it can induce on routes. Without this option the preferred route | |
707 | with MED may be determined largely by the order that routes were received | |
708 | in. | |
42fc5d26 | 709 | |
c1a54c05 QY |
710 | Setting this option will have a performance cost that may be noticeable when |
711 | there are many routes for each destination. Currently in FRR it is | |
712 | implemented in a way that scales poorly as the number of routes per | |
713 | destination increases. | |
42fc5d26 | 714 | |
c1a54c05 | 715 | The default is that this option is not set. |
42fc5d26 QY |
716 | |
717 | Note that there are other sources of indeterminism in the route selection | |
718 | process, specifically, the preference for older and already selected routes | |
8fcedbd2 | 719 | from eBGP peers, :ref:`bgp-route-selection`. |
42fc5d26 | 720 | |
c3c5a71f | 721 | .. index:: bgp always-compare-med |
29adcd50 | 722 | .. clicmd:: bgp always-compare-med |
42fc5d26 | 723 | |
c1a54c05 QY |
724 | Always compare the MED on routes, even when they were received from |
725 | different neighbouring ASes. Setting this option makes the order of | |
726 | preference of routes more defined, and should eliminate MED induced | |
727 | oscillations. | |
42fc5d26 | 728 | |
c1a54c05 | 729 | If using this option, it may also be desirable to use |
9e146a81 | 730 | :clicmd:`set metric METRIC` to set MED to 0 on routes received from external |
c1a54c05 | 731 | neighbours. |
42fc5d26 | 732 | |
9e146a81 QY |
733 | This option can be used, together with :clicmd:`set metric METRIC` to use |
734 | MED as an intra-AS metric to steer equal-length AS_PATH routes to, e.g., | |
735 | desired exit points. | |
42fc5d26 | 736 | |
efcb2ebb | 737 | |
738 | .. _bgp-graceful-restart: | |
739 | ||
740 | Graceful Restart | |
741 | ---------------- | |
742 | ||
743 | BGP graceful restart functionality as defined in | |
744 | `RFC-4724 <https://tools.ietf.org/html/rfc4724/>`_ defines the mechanisms that | |
745 | allows BGP speaker to continue to forward data packets along known routes | |
746 | while the routing protocol information is being restored. | |
747 | ||
748 | ||
749 | Usually, when BGP on a router restarts, all the BGP peers detect that the | |
750 | session went down and then came up. This "down/up" transition results in a | |
751 | "routing flap" and causes BGP route re-computation, generation of BGP routing | |
752 | updates, and unnecessary churn to the forwarding tables. | |
753 | ||
754 | The following functionality is provided by graceful restart: | |
755 | ||
756 | 1. The feature allows the restarting router to indicate to the helping peer the | |
757 | routes it can preserve in its forwarding plane during control plane restart | |
758 | by sending graceful restart capability in the OPEN message sent during | |
759 | session establishment. | |
760 | 2. The feature allows helping router to advertise to all other peers the routes | |
761 | received from the restarting router which are preserved in the forwarding | |
762 | plane of the restarting router during control plane restart. | |
763 | ||
764 | ||
765 | :: | |
766 | ||
767 | ||
768 | ||
769 | (R1)-----------------------------------------------------------------(R2) | |
770 | ||
771 | 1. BGP Graceful Restart Capability exchanged between R1 & R2. | |
772 | ||
773 | <---------------------------------------------------------------------> | |
774 | ||
775 | 2. Kill BGP Process at R1. | |
776 | ||
777 | ----------------------------------------------------------------------> | |
778 | ||
779 | 3. R2 Detects the above BGP Restart & verifies BGP Restarting | |
780 | Capability of R1. | |
781 | ||
782 | 4. Start BGP Process at R1. | |
783 | ||
784 | 5. Re-establish the BGP session between R1 & R2. | |
785 | ||
786 | <---------------------------------------------------------------------> | |
787 | ||
788 | 6. R2 Send initial route updates, followed by End-Of-Rib. | |
789 | ||
790 | <---------------------------------------------------------------------- | |
791 | ||
792 | 7. R1 was waiting for End-Of-Rib from R2 & which has been received | |
793 | now. | |
794 | ||
795 | 8. R1 now runs BGP Best-Path algorithm. Send Initial BGP Update, | |
796 | followed by End-Of Rib | |
797 | ||
798 | <---------------------------------------------------------------------> | |
799 | ||
800 | ||
801 | .. _bgp-end-of-rib-message: | |
802 | ||
803 | End-of-RIB (EOR) message | |
804 | ^^^^^^^^^^^^^^^^^^^^^^^^ | |
805 | ||
806 | An UPDATE message with no reachable Network Layer Reachability Information | |
807 | (NLRI) and empty withdrawn NLRI is specified as the End-of-RIB marker that can | |
808 | be used by a BGP speaker to indicate to its peer the completion of the initial | |
809 | routing update after the session is established. | |
810 | ||
811 | For the IPv4 unicast address family, the End-of-RIB marker is an UPDATE message | |
812 | with the minimum length. For any other address family, it is an UPDATE message | |
813 | that contains only the MP_UNREACH_NLRI attribute with no withdrawn routes for | |
814 | that <AFI, SAFI>. | |
815 | ||
816 | Although the End-of-RIB marker is specified for the purpose of BGP graceful | |
817 | restart, it is noted that the generation of such a marker upon completion of | |
818 | the initial update would be useful for routing convergence in general, and thus | |
819 | the practice is recommended. | |
820 | ||
821 | .. _bgp-route-selection-deferral-timer: | |
822 | ||
823 | Route Selection Deferral Timer | |
824 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
825 | ||
826 | Specifies the time the restarting router defers the route selection process | |
827 | after restart. | |
828 | ||
829 | Restarting Router : The usage of route election deferral timer is specified | |
830 | in https://tools.ietf.org/html/rfc4724#section-4.1 | |
831 | ||
832 | Once the session between the Restarting Speaker and the Receiving Speaker is | |
833 | re-established, the Restarting Speaker will receive and process BGP messages | |
834 | from its peers. | |
835 | ||
836 | However, it MUST defer route selection for an address family until it either. | |
837 | ||
838 | 1. Receives the End-of-RIB marker from all its peers (excluding the ones with | |
839 | the "Restart State" bit set in the received capability and excluding the ones | |
840 | that do not advertise the graceful restart capability). | |
841 | 2. The Selection_Deferral_Timer timeout. | |
842 | ||
843 | .. index:: bgp graceful-restart select-defer-time (0-3600) | |
844 | .. clicmd:: bgp graceful-restart select-defer-time (0-3600) | |
845 | ||
846 | This is command, will set deferral time to value specified. | |
847 | ||
848 | ||
849 | .. index:: bgp graceful-restart rib-stale-time (1-3600) | |
850 | .. clicmd:: bgp graceful-restart rib-stale-time (1-3600) | |
851 | ||
852 | This is command, will set the time for which stale routes are kept in RIB. | |
853 | ||
854 | .. _bgp-per-peer-graceful-restart: | |
855 | ||
856 | BGP Per Peer Graceful Restart | |
857 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
858 | ||
859 | Ability to enable and disable graceful restart, helper and no GR at all mode | |
860 | functionality at peer level. | |
861 | ||
862 | So bgp graceful restart can be enabled at modes global BGP level or at per | |
863 | peer level. There are two FSM, one for BGP GR global mode and other for peer | |
864 | per GR. | |
865 | ||
866 | Default global mode is helper and default peer per mode is inherit from global. | |
867 | If per peer mode is configured, the GR mode of this particular peer will | |
868 | override the global mode. | |
869 | ||
2ba1fe69 | 870 | .. _bgp-GR-global-mode-cmd: |
efcb2ebb | 871 | |
872 | BGP GR Global Mode Commands | |
873 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
874 | ||
875 | .. index:: bgp graceful-restart | |
876 | .. clicmd:: bgp graceful-restart | |
877 | ||
878 | This command will enable BGP graceful restart ifunctionality at the global | |
879 | level. | |
880 | ||
881 | .. index:: bgp graceful-restart disable | |
882 | .. clicmd:: bgp graceful-restart disable | |
883 | ||
884 | This command will disable both the functionality graceful restart and helper | |
885 | mode. | |
886 | ||
887 | ||
888 | .. _bgp-GR-peer-mode-cmd: | |
889 | ||
890 | BGP GR Peer Mode Commands | |
891 | ^^^^^^^^^^^^^^^^^^^^^^^^^ | |
892 | ||
893 | .. index:: neighbor A.B.C.D graceful-restart | |
894 | .. clicmd:: neighbor A.B.C.D graceful-restart | |
895 | ||
896 | This command will enable BGP graceful restart ifunctionality at the peer | |
897 | level. | |
898 | ||
899 | .. index:: neighbor A.B.C.D graceful-restart-helper | |
900 | .. clicmd:: neighbor A.B.C.D graceful-restart-helper | |
901 | ||
902 | This command will enable BGP graceful restart helper only functionality | |
903 | at the peer level. | |
904 | ||
905 | .. index:: neighbor A.B.C.D graceful-restart-disable | |
906 | .. clicmd:: neighbor A.B.C.D graceful-restart-disable | |
907 | ||
908 | This command will disable the entire BGP graceful restart functionality | |
909 | at the peer level. | |
910 | ||
911 | ||
df465afe DS |
912 | .. _bgp-shutdown: |
913 | ||
914 | Administrative Shutdown | |
915 | ----------------------- | |
916 | ||
3d13052d | 917 | .. index:: bgp shutdown [message MSG...] |
df465afe DS |
918 | .. clicmd:: [no] bgp shutdown [message MSG...] |
919 | ||
920 | Administrative shutdown of all peers of a bgp instance. Drop all BGP peers, | |
921 | but preserve their configurations. The peers are notified in accordance with | |
922 | `RFC 8203 <https://tools.ietf.org/html/rfc8203/>`_ by sending a | |
923 | ``NOTIFICATION`` message with error code ``Cease`` and subcode | |
924 | ``Administrative Shutdown`` prior to terminating connections. This global | |
925 | shutdown is independent of the neighbor shutdown, meaning that individually | |
926 | shut down peers will not be affected by lifting it. | |
927 | ||
928 | An optional shutdown message `MSG` can be specified. | |
929 | ||
930 | ||
0efdf0fe | 931 | .. _bgp-network: |
42fc5d26 | 932 | |
8fcedbd2 QY |
933 | Networks |
934 | -------- | |
42fc5d26 | 935 | |
c1a54c05 QY |
936 | .. index:: network A.B.C.D/M |
937 | .. clicmd:: network A.B.C.D/M | |
42fc5d26 | 938 | |
9eb95b3b | 939 | This command adds the announcement network. |
c3c5a71f | 940 | |
9eb95b3b QY |
941 | .. code-block:: frr |
942 | ||
943 | router bgp 1 | |
944 | address-family ipv4 unicast | |
945 | network 10.0.0.0/8 | |
946 | exit-address-family | |
42fc5d26 | 947 | |
c1a54c05 QY |
948 | This configuration example says that network 10.0.0.0/8 will be |
949 | announced to all neighbors. Some vendors' routers don't advertise | |
950 | routes if they aren't present in their IGP routing tables; `bgpd` | |
951 | doesn't care about IGP routes when announcing its routes. | |
c3c5a71f | 952 | |
3d13052d | 953 | .. index:: network A.B.C.D/M |
c1a54c05 | 954 | .. clicmd:: no network A.B.C.D/M |
42fc5d26 | 955 | |
3d13052d | 956 | .. index:: bgp network import-check |
f990a416 DS |
957 | .. clicmd:: [no] bgp network import-check |
958 | ||
959 | This configuration modifies the behavior of the network statement. | |
960 | If you have this configured the underlying network must exist in | |
961 | the rib. If you have the [no] form configured then BGP will not | |
962 | check for the networks existence in the rib. For versions 7.3 and | |
963 | before frr defaults for datacenter were the network must exist, | |
964 | traditional did not check for existence. For versions 7.4 and beyond | |
965 | both traditional and datacenter the network must exist. | |
966 | ||
ef1b6319 | 967 | .. _bgp-ipv6-support: |
547ba033 MH |
968 | |
969 | IPv6 Support | |
970 | ------------ | |
971 | ||
3d13052d | 972 | .. index:: neighbor A.B.C.D activate |
547ba033 MH |
973 | .. clicmd:: [no] neighbor A.B.C.D activate |
974 | ||
ef1b6319 | 975 | This configuration modifies whether to enable an address family for a |
547ba033 MH |
976 | specific neighbor. By default only the IPv4 unicast address family is |
977 | enabled. | |
978 | ||
979 | .. code-block:: frr | |
980 | ||
981 | router bgp 1 | |
982 | address-family ipv6 unicast | |
983 | neighbor 2001:0DB8::1 activate | |
984 | network 2001:0DB8:5009::/64 | |
985 | exit-address-family | |
986 | ||
987 | This configuration example says that network 2001:0DB8:5009::/64 will be | |
988 | announced and enables the neighbor 2001:0DB8::1 to receive this announcement. | |
989 | ||
547ba033 MH |
990 | By default, only the IPv4 unicast address family is announced to all |
991 | neighbors. Using the 'no bgp default ipv4-unicast' configuration overrides | |
992 | this default so that all address families need to be enabled explicitly. | |
993 | ||
994 | .. code-block:: frr | |
995 | ||
996 | router bgp 1 | |
997 | no bgp default ipv4-unicast | |
998 | neighbor 10.10.10.1 remote-as 2 | |
999 | neighbor 2001:0DB8::1 remote-as 3 | |
1000 | address-family ipv4 unicast | |
1001 | neighbor 10.10.10.1 activate | |
1002 | network 192.168.1.0/24 | |
1003 | exit-address-family | |
1004 | address-family ipv6 unicast | |
1005 | neighbor 2001:0DB8::1 activate | |
1006 | network 2001:0DB8:5009::/64 | |
1007 | exit-address-family | |
1008 | ||
1009 | This configuration demonstrates how the 'no bgp default ipv4-unicast' might | |
1010 | be used in a setup with two upstreams where each of the upstreams should only | |
1011 | receive either IPv4 or IPv6 annocuments. | |
1012 | ||
1013 | ||
8fcedbd2 | 1014 | .. _bgp-route-aggregation: |
42fc5d26 QY |
1015 | |
1016 | Route Aggregation | |
1017 | ----------------- | |
1018 | ||
5101fece | 1019 | .. _bgp-route-aggregation-ipv4: |
1020 | ||
1021 | Route Aggregation-IPv4 Address Family | |
1022 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
1023 | ||
c1a54c05 QY |
1024 | .. index:: aggregate-address A.B.C.D/M |
1025 | .. clicmd:: aggregate-address A.B.C.D/M | |
c3c5a71f | 1026 | |
c1a54c05 | 1027 | This command specifies an aggregate address. |
42fc5d26 | 1028 | |
ac2201bb DA |
1029 | .. index:: aggregate-address A.B.C.D/M route-map NAME |
1030 | .. clicmd:: aggregate-address A.B.C.D/M route-map NAME | |
1031 | ||
1032 | Apply a route-map for an aggregated prefix. | |
1033 | ||
a87d2ef7 DA |
1034 | .. index:: aggregate-address A.B.C.D/M origin <egp|igp|incomplete> |
1035 | .. clicmd:: aggregate-address A.B.C.D/M origin <egp|igp|incomplete> | |
1036 | ||
1037 | Override ORIGIN for an aggregated prefix. | |
1038 | ||
c1a54c05 QY |
1039 | .. index:: aggregate-address A.B.C.D/M as-set |
1040 | .. clicmd:: aggregate-address A.B.C.D/M as-set | |
42fc5d26 | 1041 | |
c1a54c05 QY |
1042 | This command specifies an aggregate address. Resulting routes include |
1043 | AS set. | |
42fc5d26 | 1044 | |
c1a54c05 QY |
1045 | .. index:: aggregate-address A.B.C.D/M summary-only |
1046 | .. clicmd:: aggregate-address A.B.C.D/M summary-only | |
c3c5a71f | 1047 | |
d1e7591e | 1048 | This command specifies an aggregate address. Aggregated routes will |
b91bf5bd | 1049 | not be announced. |
42fc5d26 | 1050 | |
01338ba1 RZ |
1051 | .. index:: aggregate-address A.B.C.D/M matching-MED-only |
1052 | .. clicmd:: aggregate-address A.B.C.D/M matching-MED-only | |
1053 | ||
1054 | Configure the aggregated address to only be created when the routes MED | |
1055 | match, otherwise no aggregated route will be created. | |
1056 | ||
8fbb9c95 RZ |
1057 | .. index:: aggregate-address A.B.C.D/M suppress-map NAME |
1058 | .. clicmd:: aggregate-address A.B.C.D/M suppress-map NAME | |
1059 | ||
1060 | Similar to `summary-only`, but will only suppress more specific routes that | |
1061 | are matched by the selected route-map. | |
1062 | ||
3d13052d | 1063 | .. index:: aggregate-address A.B.C.D/M |
c1a54c05 | 1064 | .. clicmd:: no aggregate-address A.B.C.D/M |
ac2201bb | 1065 | |
5101fece | 1066 | This command removes an aggregate address. |
1067 | ||
1068 | ||
ac2201bb | 1069 | This configuration example setup the aggregate-address under |
5101fece | 1070 | ipv4 address-family. |
1071 | ||
1072 | .. code-block:: frr | |
1073 | ||
1074 | router bgp 1 | |
1075 | address-family ipv4 unicast | |
1076 | aggregate-address 10.0.0.0/8 | |
1077 | aggregate-address 20.0.0.0/8 as-set | |
1078 | aggregate-address 40.0.0.0/8 summary-only | |
ac2201bb | 1079 | aggregate-address 50.0.0.0/8 route-map aggr-rmap |
5101fece | 1080 | exit-address-family |
1081 | ||
1082 | ||
1083 | .. _bgp-route-aggregation-ipv6: | |
1084 | ||
1085 | Route Aggregation-IPv6 Address Family | |
1086 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
1087 | ||
1088 | .. index:: aggregate-address X:X::X:X/M | |
1089 | .. clicmd:: aggregate-address X:X::X:X/M | |
1090 | ||
1091 | This command specifies an aggregate address. | |
1092 | ||
ac2201bb DA |
1093 | .. index:: aggregate-address X:X::X:X/M route-map NAME |
1094 | .. clicmd:: aggregate-address X:X::X:X/M route-map NAME | |
1095 | ||
1096 | Apply a route-map for an aggregated prefix. | |
1097 | ||
a87d2ef7 DA |
1098 | .. index:: aggregate-address X:X::X:X/M origin <egp|igp|incomplete> |
1099 | .. clicmd:: aggregate-address X:X::X:X/M origin <egp|igp|incomplete> | |
1100 | ||
1101 | Override ORIGIN for an aggregated prefix. | |
1102 | ||
5101fece | 1103 | .. index:: aggregate-address X:X::X:X/M as-set |
1104 | .. clicmd:: aggregate-address X:X::X:X/M as-set | |
1105 | ||
1106 | This command specifies an aggregate address. Resulting routes include | |
1107 | AS set. | |
1108 | ||
1109 | .. index:: aggregate-address X:X::X:X/M summary-only | |
1110 | .. clicmd:: aggregate-address X:X::X:X/M summary-only | |
1111 | ||
1112 | This command specifies an aggregate address. Aggregated routes will | |
b91bf5bd | 1113 | not be announced. |
5101fece | 1114 | |
01338ba1 RZ |
1115 | .. index:: aggregate-address X:X::X:X/M matching-MED-only |
1116 | .. clicmd:: aggregate-address X:X::X:X/M matching-MED-only | |
1117 | ||
1118 | Configure the aggregated address to only be created when the routes MED | |
1119 | match, otherwise no aggregated route will be created. | |
1120 | ||
8fbb9c95 RZ |
1121 | .. index:: aggregate-address X:X::X:X/M suppress-map NAME |
1122 | .. clicmd:: aggregate-address X:X::X:X/M suppress-map NAME | |
1123 | ||
1124 | Similar to `summary-only`, but will only suppress more specific routes that | |
1125 | are matched by the selected route-map. | |
01338ba1 | 1126 | |
3d13052d | 1127 | .. index:: aggregate-address X:X::X:X/M |
5101fece | 1128 | .. clicmd:: no aggregate-address X:X::X:X/M |
1129 | ||
1130 | This command removes an aggregate address. | |
1131 | ||
1132 | ||
ac2201bb DA |
1133 | This configuration example setup the aggregate-address under |
1134 | ipv6 address-family. | |
5101fece | 1135 | |
1136 | .. code-block:: frr | |
1137 | ||
1138 | router bgp 1 | |
1139 | address-family ipv6 unicast | |
1140 | aggregate-address 10::0/64 | |
ac2201bb DA |
1141 | aggregate-address 20::0/64 as-set |
1142 | aggregate-address 40::0/64 summary-only | |
1143 | aggregate-address 50::0/64 route-map aggr-rmap | |
5101fece | 1144 | exit-address-family |
c3c5a71f | 1145 | |
8fcedbd2 | 1146 | .. _bgp-redistribute-to-bgp: |
42fc5d26 | 1147 | |
8fcedbd2 QY |
1148 | Redistribution |
1149 | -------------- | |
42fc5d26 | 1150 | |
c3c5a71f | 1151 | .. index:: redistribute kernel |
29adcd50 | 1152 | .. clicmd:: redistribute kernel |
42fc5d26 | 1153 | |
c1a54c05 | 1154 | Redistribute kernel route to BGP process. |
42fc5d26 | 1155 | |
c3c5a71f | 1156 | .. index:: redistribute static |
29adcd50 | 1157 | .. clicmd:: redistribute static |
42fc5d26 | 1158 | |
c1a54c05 | 1159 | Redistribute static route to BGP process. |
42fc5d26 | 1160 | |
c3c5a71f | 1161 | .. index:: redistribute connected |
29adcd50 | 1162 | .. clicmd:: redistribute connected |
42fc5d26 | 1163 | |
c1a54c05 | 1164 | Redistribute connected route to BGP process. |
42fc5d26 | 1165 | |
c3c5a71f | 1166 | .. index:: redistribute rip |
29adcd50 | 1167 | .. clicmd:: redistribute rip |
42fc5d26 | 1168 | |
c1a54c05 | 1169 | Redistribute RIP route to BGP process. |
42fc5d26 | 1170 | |
c3c5a71f | 1171 | .. index:: redistribute ospf |
29adcd50 | 1172 | .. clicmd:: redistribute ospf |
42fc5d26 | 1173 | |
c1a54c05 | 1174 | Redistribute OSPF route to BGP process. |
42fc5d26 | 1175 | |
99ad55e0 DA |
1176 | .. index:: redistribute vnc |
1177 | .. clicmd:: redistribute vnc | |
42fc5d26 | 1178 | |
c1a54c05 | 1179 | Redistribute VNC routes to BGP process. |
42fc5d26 | 1180 | |
245d354f DA |
1181 | .. index:: redistribute vnc-direct |
1182 | .. clicmd:: redistribute vnc-direct | |
1183 | ||
1184 | Redistribute VNC direct (not via zebra) routes to BGP process. | |
1185 | ||
d70583f7 D |
1186 | .. index:: bgp update-delay MAX-DELAY |
1187 | .. clicmd:: bgp update-delay MAX-DELAY | |
1188 | ||
1189 | .. index:: bgp update-delay MAX-DELAY ESTABLISH-WAIT | |
1190 | .. clicmd:: bgp update-delay MAX-DELAY ESTABLISH-WAIT | |
1191 | ||
1192 | This feature is used to enable read-only mode on BGP process restart or when | |
1193 | a BGP process is cleared using 'clear ip bgp \*'. Note that this command is | |
1194 | configured at the global level and applies to all bgp instances/vrfs. It | |
1195 | cannot be used at the same time as the "update-delay" command described below, | |
1196 | which is entered in each bgp instance/vrf desired to delay update installation | |
1197 | and advertisements. The global and per-vrf approaches to defining update-delay | |
1198 | are mutually exclusive. | |
1199 | ||
1200 | When applicable, read-only mode would begin as soon as the first peer reaches | |
1201 | Established status and a timer for max-delay seconds is started. During this | |
1202 | mode BGP doesn't run any best-path or generate any updates to its peers. This | |
1203 | mode continues until: | |
1204 | ||
1205 | 1. All the configured peers, except the shutdown peers, have sent explicit EOR | |
1206 | (End-Of-RIB) or an implicit-EOR. The first keep-alive after BGP has reached | |
1207 | Established is considered an implicit-EOR. | |
1208 | If the establish-wait optional value is given, then BGP will wait for | |
1209 | peers to reach established from the beginning of the update-delay till the | |
1210 | establish-wait period is over, i.e. the minimum set of established peers for | |
1211 | which EOR is expected would be peers established during the establish-wait | |
1212 | window, not necessarily all the configured neighbors. | |
1213 | 2. max-delay period is over. | |
1214 | ||
1215 | On hitting any of the above two conditions, BGP resumes the decision process | |
1216 | and generates updates to its peers. | |
1217 | ||
1218 | Default max-delay is 0, i.e. the feature is off by default. | |
1219 | ||
1220 | ||
c1a54c05 QY |
1221 | .. index:: update-delay MAX-DELAY |
1222 | .. clicmd:: update-delay MAX-DELAY | |
c3c5a71f | 1223 | |
c1a54c05 QY |
1224 | .. index:: update-delay MAX-DELAY ESTABLISH-WAIT |
1225 | .. clicmd:: update-delay MAX-DELAY ESTABLISH-WAIT | |
c3c5a71f | 1226 | |
c1a54c05 | 1227 | This feature is used to enable read-only mode on BGP process restart or when |
d70583f7 D |
1228 | a BGP process is cleared using 'clear ip bgp \*'. Note that this command is |
1229 | configured under the specific bgp instance/vrf that the feaure is enabled for. | |
1230 | It cannot be used at the same time as the global "bgp update-delay" described | |
1231 | above, which is entered at the global level and applies to all bgp instances. | |
1232 | The global and per-vrf approaches to defining update-delay are mutually | |
1233 | exclusive. | |
1234 | ||
1235 | When applicable, read-only mode would begin as soon as the first peer reaches | |
1236 | Established status and a timer for max-delay seconds is started. During this | |
1237 | mode BGP doesn't run any best-path or generate any updates to its peers. This | |
1238 | mode continues until: | |
42fc5d26 | 1239 | |
c1a54c05 QY |
1240 | 1. All the configured peers, except the shutdown peers, have sent explicit EOR |
1241 | (End-Of-RIB) or an implicit-EOR. The first keep-alive after BGP has reached | |
1242 | Established is considered an implicit-EOR. | |
1243 | If the establish-wait optional value is given, then BGP will wait for | |
d1e7591e | 1244 | peers to reach established from the beginning of the update-delay till the |
c1a54c05 QY |
1245 | establish-wait period is over, i.e. the minimum set of established peers for |
1246 | which EOR is expected would be peers established during the establish-wait | |
1247 | window, not necessarily all the configured neighbors. | |
1248 | 2. max-delay period is over. | |
42fc5d26 | 1249 | |
c1a54c05 QY |
1250 | On hitting any of the above two conditions, BGP resumes the decision process |
1251 | and generates updates to its peers. | |
42fc5d26 | 1252 | |
c1a54c05 | 1253 | Default max-delay is 0, i.e. the feature is off by default. |
c3c5a71f | 1254 | |
c1a54c05 QY |
1255 | .. index:: table-map ROUTE-MAP-NAME |
1256 | .. clicmd:: table-map ROUTE-MAP-NAME | |
42fc5d26 | 1257 | |
c1a54c05 QY |
1258 | This feature is used to apply a route-map on route updates from BGP to |
1259 | Zebra. All the applicable match operations are allowed, such as match on | |
1260 | prefix, next-hop, communities, etc. Set operations for this attach-point are | |
1261 | limited to metric and next-hop only. Any operation of this feature does not | |
1262 | affect BGPs internal RIB. | |
42fc5d26 | 1263 | |
c1a54c05 QY |
1264 | Supported for ipv4 and ipv6 address families. It works on multi-paths as |
1265 | well, however, metric setting is based on the best-path only. | |
42fc5d26 | 1266 | |
8fcedbd2 | 1267 | .. _bgp-peers: |
42fc5d26 | 1268 | |
8fcedbd2 QY |
1269 | Peers |
1270 | ----- | |
42fc5d26 | 1271 | |
8fcedbd2 | 1272 | .. _bgp-defining-peers: |
42fc5d26 | 1273 | |
8fcedbd2 QY |
1274 | Defining Peers |
1275 | ^^^^^^^^^^^^^^ | |
42fc5d26 | 1276 | |
c1a54c05 QY |
1277 | .. index:: neighbor PEER remote-as ASN |
1278 | .. clicmd:: neighbor PEER remote-as ASN | |
42fc5d26 | 1279 | |
c1a54c05 | 1280 | Creates a new neighbor whose remote-as is ASN. PEER can be an IPv4 address |
9eb95b3b | 1281 | or an IPv6 address or an interface to use for the connection. |
76bd1499 | 1282 | |
9eb95b3b QY |
1283 | .. code-block:: frr |
1284 | ||
1285 | router bgp 1 | |
1286 | neighbor 10.0.0.1 remote-as 2 | |
76bd1499 | 1287 | |
c1a54c05 | 1288 | In this case my router, in AS-1, is trying to peer with AS-2 at 10.0.0.1. |
76bd1499 | 1289 | |
c1a54c05 | 1290 | This command must be the first command used when configuring a neighbor. If |
9eb95b3b | 1291 | the remote-as is not specified, *bgpd* will complain like this: :: |
76bd1499 | 1292 | |
c1a54c05 | 1293 | can't find neighbor 10.0.0.1 |
c3c5a71f | 1294 | |
5413757f DS |
1295 | .. index:: neighbor PEER remote-as internal |
1296 | .. clicmd:: neighbor PEER remote-as internal | |
1297 | ||
1298 | Create a peer as you would when you specify an ASN, except that if the | |
1299 | peers ASN is different than mine as specified under the :clicmd:`router bgp ASN` | |
1300 | command the connection will be denied. | |
1301 | ||
1302 | .. index:: neighbor PEER remote-as external | |
1303 | .. clicmd:: neighbor PEER remote-as external | |
1304 | ||
1305 | Create a peer as you would when you specify an ASN, except that if the | |
1306 | peers ASN is the same as mine as specified under the :clicmd:`router bgp ASN` | |
1307 | command the connection will be denied. | |
42fc5d26 | 1308 | |
3d13052d | 1309 | .. index:: bgp listen range <A.B.C.D/M|X:X::X:X/M> peer-group PGNAME |
d7b9898c | 1310 | .. clicmd:: [no] bgp listen range <A.B.C.D/M|X:X::X:X/M> peer-group PGNAME |
d79e0e08 QY |
1311 | |
1312 | Accept connections from any peers in the specified prefix. Configuration | |
1313 | from the specified peer-group is used to configure these peers. | |
1314 | ||
1315 | .. note:: | |
1316 | ||
1317 | When using BGP listen ranges, if the associated peer group has TCP MD5 | |
1318 | authentication configured, your kernel must support this on prefixes. On | |
1319 | Linux, this support was added in kernel version 4.14. If your kernel does | |
1320 | not support this feature you will get a warning in the log file, and the | |
1321 | listen range will only accept connections from peers without MD5 configured. | |
1322 | ||
1323 | Additionally, we have observed that when using this option at scale (several | |
1324 | hundred peers) the kernel may hit its option memory limit. In this situation | |
1325 | you will see error messages like: | |
1326 | ||
1327 | ``bgpd: sockopt_tcp_signature: setsockopt(23): Cannot allocate memory`` | |
1328 | ||
1329 | In this case you need to increase the value of the sysctl | |
1330 | ``net.core.optmem_max`` to allow the kernel to allocate the necessary option | |
1331 | memory. | |
1332 | ||
3d13052d | 1333 | .. index:: coalesce-time (0-4294967295) |
ced26d3d DS |
1334 | .. clicmd:: [no] coalesce-time (0-4294967295) |
1335 | ||
1336 | The time in milliseconds that BGP will delay before deciding what peers | |
1337 | can be put into an update-group together in order to generate a single | |
1338 | update for them. The default time is 1000. | |
91052810 | 1339 | |
8fcedbd2 | 1340 | .. _bgp-configuring-peers: |
42fc5d26 | 1341 | |
8fcedbd2 QY |
1342 | Configuring Peers |
1343 | ^^^^^^^^^^^^^^^^^ | |
42fc5d26 | 1344 | |
3d13052d | 1345 | .. index:: neighbor PEER shutdown [message MSG...] [rtt (1-65535) [count (1-255)]] |
91052810 | 1346 | .. clicmd:: [no] neighbor PEER shutdown [message MSG...] [rtt (1-65535) [count (1-255)]] |
c3c5a71f | 1347 | |
c1a54c05 QY |
1348 | Shutdown the peer. We can delete the neighbor's configuration by |
1349 | ``no neighbor PEER remote-as ASN`` but all configuration of the neighbor | |
1350 | will be deleted. When you want to preserve the configuration, but want to | |
1351 | drop the BGP peer, use this syntax. | |
c3c5a71f | 1352 | |
70335e0a RZ |
1353 | Optionally you can specify a shutdown message `MSG`. |
1354 | ||
56c07345 | 1355 | Also, you can specify optionally ``rtt`` in milliseconds to automatically |
91052810 DA |
1356 | shutdown the peer if round-trip-time becomes higher than defined. |
1357 | ||
56c07345 | 1358 | Additional ``count`` parameter is the number of keepalive messages to count |
91052810 DA |
1359 | before shutdown the peer if round-trip-time becomes higher than defined. |
1360 | ||
3d13052d | 1361 | .. index:: neighbor PEER disable-connected-check |
c0868e8b | 1362 | .. clicmd:: [no] neighbor PEER disable-connected-check |
c3c5a71f | 1363 | |
c0868e8b QY |
1364 | Allow peerings between directly connected eBGP peers using loopback |
1365 | addresses. | |
c3c5a71f | 1366 | |
3d13052d | 1367 | .. index:: neighbor PEER ebgp-multihop |
c0868e8b | 1368 | .. clicmd:: [no] neighbor PEER ebgp-multihop |
42fc5d26 | 1369 | |
164786a9 QY |
1370 | Specifying ``ebgp-multihop`` allows sessions with eBGP neighbors to |
1371 | establish when they are multiple hops away. When the neighbor is not | |
1372 | directly connected and this knob is not enabled, the session will not | |
1373 | establish. | |
1374 | ||
3d13052d | 1375 | .. index:: neighbor PEER description ... |
c0868e8b | 1376 | .. clicmd:: [no] neighbor PEER description ... |
42fc5d26 | 1377 | |
c1a54c05 | 1378 | Set description of the peer. |
42fc5d26 | 1379 | |
3d13052d | 1380 | .. index:: neighbor PEER version VERSION |
c0868e8b | 1381 | .. clicmd:: [no] neighbor PEER version VERSION |
42fc5d26 | 1382 | |
4da7fda3 QY |
1383 | Set up the neighbor's BGP version. `version` can be `4`, `4+` or `4-`. BGP |
1384 | version `4` is the default value used for BGP peering. BGP version `4+` | |
1385 | means that the neighbor supports Multiprotocol Extensions for BGP-4. BGP | |
1386 | version `4-` is similar but the neighbor speaks the old Internet-Draft | |
1387 | revision 00's Multiprotocol Extensions for BGP-4. Some routing software is | |
1388 | still using this version. | |
42fc5d26 | 1389 | |
3d13052d | 1390 | .. index:: neighbor PEER interface IFNAME |
c0868e8b | 1391 | .. clicmd:: [no] neighbor PEER interface IFNAME |
42fc5d26 | 1392 | |
c1a54c05 QY |
1393 | When you connect to a BGP peer over an IPv6 link-local address, you have to |
1394 | specify the IFNAME of the interface used for the connection. To specify | |
1395 | IPv4 session addresses, see the ``neighbor PEER update-source`` command | |
1396 | below. | |
42fc5d26 | 1397 | |
c1a54c05 QY |
1398 | This command is deprecated and may be removed in a future release. Its use |
1399 | should be avoided. | |
42fc5d26 | 1400 | |
3d13052d | 1401 | .. index:: neighbor PEER next-hop-self [all] |
c0868e8b | 1402 | .. clicmd:: [no] neighbor PEER next-hop-self [all] |
42fc5d26 | 1403 | |
c1a54c05 QY |
1404 | This command specifies an announced route's nexthop as being equivalent to |
1405 | the address of the bgp router if it is learned via eBGP. If the optional | |
d1e7591e | 1406 | keyword `all` is specified the modification is done also for routes learned |
c1a54c05 | 1407 | via iBGP. |
42fc5d26 | 1408 | |
8b0d734b | 1409 | .. index:: neighbor PEER attribute-unchanged [{as-path|next-hop|med}] |
1410 | .. clicmd:: neighbor PEER attribute-unchanged [{as-path|next-hop|med}] | |
1411 | ||
1412 | This command specifies attributes to be left unchanged for advertisements | |
1413 | sent to a peer. Use this to leave the next-hop unchanged in ipv6 | |
1414 | configurations, as the route-map directive to leave the next-hop unchanged | |
1415 | is only available for ipv4. | |
1416 | ||
3d13052d | 1417 | .. index:: neighbor PEER update-source <IFNAME|ADDRESS> |
c0868e8b | 1418 | .. clicmd:: [no] neighbor PEER update-source <IFNAME|ADDRESS> |
42fc5d26 | 1419 | |
c1a54c05 QY |
1420 | Specify the IPv4 source address to use for the :abbr:`BGP` session to this |
1421 | neighbour, may be specified as either an IPv4 address directly or as an | |
1422 | interface name (in which case the *zebra* daemon MUST be running in order | |
9eb95b3b QY |
1423 | for *bgpd* to be able to retrieve interface state). |
1424 | ||
1425 | .. code-block:: frr | |
42fc5d26 | 1426 | |
c1a54c05 QY |
1427 | router bgp 64555 |
1428 | neighbor foo update-source 192.168.0.1 | |
1429 | neighbor bar update-source lo0 | |
42fc5d26 | 1430 | |
42fc5d26 | 1431 | |
3d13052d | 1432 | .. index:: neighbor PEER default-originate |
c0868e8b | 1433 | .. clicmd:: [no] neighbor PEER default-originate |
42fc5d26 | 1434 | |
4da7fda3 QY |
1435 | *bgpd*'s default is to not announce the default route (0.0.0.0/0) even if it |
1436 | is in routing table. When you want to announce default routes to the peer, | |
1437 | use this command. | |
42fc5d26 | 1438 | |
c1a54c05 QY |
1439 | .. index:: neighbor PEER port PORT |
1440 | .. clicmd:: neighbor PEER port PORT | |
42fc5d26 | 1441 | |
3d13052d | 1442 | .. index:: neighbor PEER password PASSWORD |
e7c105a7 DS |
1443 | .. clicmd:: [no] neighbor PEER password PASSWORD |
1444 | ||
1445 | Set a MD5 password to be used with the tcp socket that is being used | |
1446 | to connect to the remote peer. Please note if you are using this | |
1447 | command with a large number of peers on linux you should consider | |
1448 | modifying the `net.core.optmem_max` sysctl to a larger value to | |
1449 | avoid out of memory errors from the linux kernel. | |
1450 | ||
c1a54c05 QY |
1451 | .. index:: neighbor PEER send-community |
1452 | .. clicmd:: neighbor PEER send-community | |
42fc5d26 | 1453 | |
3d13052d | 1454 | .. index:: neighbor PEER weight WEIGHT |
c0868e8b | 1455 | .. clicmd:: [no] neighbor PEER weight WEIGHT |
42fc5d26 | 1456 | |
c1a54c05 | 1457 | This command specifies a default `weight` value for the neighbor's routes. |
42fc5d26 | 1458 | |
3d13052d | 1459 | .. index:: neighbor PEER maximum-prefix NUMBER [force] |
c1bcac1d | 1460 | .. clicmd:: [no] neighbor PEER maximum-prefix NUMBER [force] |
42fc5d26 | 1461 | |
886026c8 QY |
1462 | Sets a maximum number of prefixes we can receive from a given peer. If this |
1463 | number is exceeded, the BGP session will be destroyed. | |
1464 | ||
1465 | In practice, it is generally preferable to use a prefix-list to limit what | |
1466 | prefixes are received from the peer instead of using this knob. Tearing down | |
1467 | the BGP session when a limit is exceeded is far more destructive than merely | |
1468 | rejecting undesired prefixes. The prefix-list method is also much more | |
1469 | granular and offers much smarter matching criterion than number of received | |
1470 | prefixes, making it more suited to implementing policy. | |
1471 | ||
56c07345 | 1472 | If ``force`` is set, then ALL prefixes are counted for maximum instead of |
c1bcac1d DA |
1473 | accepted only. This is useful for cases where an inbound filter is applied, |
1474 | but you want maximum-prefix to act on ALL (including filtered) prefixes. This | |
1475 | option requires `soft-reconfiguration inbound` to be enabled for the peer. | |
1476 | ||
3d13052d | 1477 | .. index:: neighbor PEER maximum-prefix-out NUMBER |
edf98aa3 DA |
1478 | .. clicmd:: [no] neighbor PEER maximum-prefix-out NUMBER |
1479 | ||
1480 | Sets a maximum number of prefixes we can send to a given peer. | |
1481 | ||
f5399474 DA |
1482 | Since sent prefix count is managed by update-groups, this option |
1483 | creates a separate update-group for outgoing updates. | |
1484 | ||
3d13052d | 1485 | .. index:: neighbor PEER local-as AS-NUMBER [no-prepend] [replace-as] |
886026c8 | 1486 | .. clicmd:: [no] neighbor PEER local-as AS-NUMBER [no-prepend] [replace-as] |
42fc5d26 | 1487 | |
c1a54c05 QY |
1488 | Specify an alternate AS for this BGP process when interacting with the |
1489 | specified peer. With no modifiers, the specified local-as is prepended to | |
1490 | the received AS_PATH when receiving routing updates from the peer, and | |
1491 | prepended to the outgoing AS_PATH (after the process local AS) when | |
1492 | transmitting local routes to the peer. | |
42fc5d26 | 1493 | |
c1a54c05 QY |
1494 | If the no-prepend attribute is specified, then the supplied local-as is not |
1495 | prepended to the received AS_PATH. | |
c3c5a71f | 1496 | |
c1a54c05 QY |
1497 | If the replace-as attribute is specified, then only the supplied local-as is |
1498 | prepended to the AS_PATH when transmitting local-route updates to this peer. | |
c3c5a71f | 1499 | |
c1a54c05 | 1500 | Note that replace-as can only be specified if no-prepend is. |
c3c5a71f | 1501 | |
c1a54c05 | 1502 | This command is only allowed for eBGP peers. |
c3c5a71f | 1503 | |
3d13052d | 1504 | .. index:: neighbor <A.B.C.D|X:X::X:X|WORD> as-override |
252c5590 RZ |
1505 | .. clicmd:: [no] neighbor <A.B.C.D|X:X::X:X|WORD> as-override |
1506 | ||
1507 | Override AS number of the originating router with the local AS number. | |
1508 | ||
1509 | Usually this configuration is used in PEs (Provider Edge) to replace | |
1510 | the incoming customer AS number so the connected CE (Customer Edge) | |
1511 | can use the same AS number as the other customer sites. This allows | |
1512 | customers of the provider network to use the same AS number across | |
1513 | their sites. | |
1514 | ||
1515 | This command is only allowed for eBGP peers. | |
1516 | ||
3d13052d | 1517 | .. index:: neighbor <A.B.C.D|X:X::X:X|WORD> allowas-in [<(1-10)|origin>] |
ae1e0f32 RZ |
1518 | .. clicmd:: [no] neighbor <A.B.C.D|X:X::X:X|WORD> allowas-in [<(1-10)|origin>] |
1519 | ||
1520 | Accept incoming routes with AS path containing AS number with the same value | |
1521 | as the current system AS. | |
1522 | ||
1523 | This is used when you want to use the same AS number in your sites, but you | |
1524 | can't connect them directly. This is an alternative to | |
1525 | `neighbor WORD as-override`. | |
1526 | ||
1527 | The parameter `(1-10)` configures the amount of accepted occurences of the | |
1528 | system AS number in AS path. | |
1529 | ||
1530 | The parameter `origin` configures BGP to only accept routes originated with | |
1531 | the same AS number as the system. | |
1532 | ||
1533 | This command is only allowed for eBGP peers. | |
1534 | ||
3d13052d | 1535 | .. index:: neighbor <A.B.C.D|X:X::X:X|WORD> addpath-tx-all-paths |
e03bf6fc RZ |
1536 | .. clicmd:: [no] neighbor <A.B.C.D|X:X::X:X|WORD> addpath-tx-all-paths |
1537 | ||
1538 | Configure BGP to send all known paths to neighbor in order to preserve multi | |
1539 | path capabilities inside a network. | |
1540 | ||
3d13052d | 1541 | .. index:: neighbor <A.B.C.D|X:X::X:X|WORD> addpath-tx-bestpath-per-AS |
e03bf6fc RZ |
1542 | .. clicmd:: [no] neighbor <A.B.C.D|X:X::X:X|WORD> addpath-tx-bestpath-per-AS |
1543 | ||
1544 | Configure BGP to send best known paths to neighbor in order to preserve multi | |
1545 | path capabilities inside a network. | |
1546 | ||
3d13052d | 1547 | .. index:: neighbor PEER ttl-security hops NUMBER |
c0868e8b | 1548 | .. clicmd:: [no] neighbor PEER ttl-security hops NUMBER |
c3c5a71f | 1549 | |
c1a54c05 QY |
1550 | This command enforces Generalized TTL Security Mechanism (GTSM), as |
1551 | specified in RFC 5082. With this command, only neighbors that are the | |
1552 | specified number of hops away will be allowed to become neighbors. This | |
d1e7591e | 1553 | command is mutually exclusive with *ebgp-multihop*. |
42fc5d26 | 1554 | |
3d13052d | 1555 | .. index:: neighbor PEER capability extended-nexthop |
19f2b5e8 DS |
1556 | .. clicmd:: [no] neighbor PEER capability extended-nexthop |
1557 | ||
1558 | Allow bgp to negotiate the extended-nexthop capability with it's peer. | |
1559 | If you are peering over a v6 LL address then this capability is turned | |
1560 | on automatically. If you are peering over a v6 Global Address then | |
1561 | turning on this command will allow BGP to install v4 routes with | |
1562 | v6 nexthops if you do not have v4 configured on interfaces. | |
1563 | ||
3d13052d | 1564 | .. index:: bgp fast-external-failover |
eb938189 DS |
1565 | .. clicmd:: [no] bgp fast-external-failover |
1566 | ||
1567 | This command causes bgp to not take down ebgp peers immediately | |
1568 | when a link flaps. `bgp fast-external-failover` is the default | |
1569 | and will not be displayed as part of a `show run`. The no form | |
1570 | of the command turns off this ability. | |
1571 | ||
3d13052d | 1572 | .. index:: bgp default ipv4-unicast |
bc132029 DS |
1573 | .. clicmd:: [no] bgp default ipv4-unicast |
1574 | ||
1575 | This command allows the user to specify that v4 peering is turned | |
1576 | on by default or not. This command defaults to on and is not displayed. | |
1577 | The `no bgp default ipv4-unicast` form of the command is displayed. | |
1578 | ||
3d13052d | 1579 | .. index:: bgp default show-hostname |
7d981695 DA |
1580 | .. clicmd:: [no] bgp default show-hostname |
1581 | ||
1582 | This command shows the hostname of the peer in certain BGP commands | |
1583 | outputs. It's easier to troubleshoot if you have a number of BGP peers. | |
1584 | ||
3d13052d | 1585 | .. index:: bgp default show-nexthop-hostname |
7d981695 DA |
1586 | .. clicmd:: [no] bgp default show-nexthop-hostname |
1587 | ||
1588 | This command shows the hostname of the next-hop in certain BGP commands | |
1589 | outputs. It's easier to troubleshoot if you have a number of BGP peers | |
1590 | and a number of routes to check. | |
1591 | ||
3d13052d | 1592 | .. index:: neighbor PEER advertisement-interval (0-600) |
e10dda57 DS |
1593 | .. clicmd:: [no] neighbor PEER advertisement-interval (0-600) |
1594 | ||
1595 | Setup the minimum route advertisement interval(mrai) for the | |
1596 | peer in question. This number is between 0 and 600 seconds, | |
1597 | with the default advertisement interval being 0. | |
1598 | ||
94abf9b4 DS |
1599 | .. index:: [no] neighbor PEER timers delayopen (1-240) |
1600 | .. clicmd:: [no] neighbor PEER timers delayopen (1-240) | |
1601 | ||
1602 | This command allows the user enable the | |
1603 | `RFC 4271 <https://tools.ietf.org/html/rfc4271/>` DelayOpenTimer with the | |
1604 | specified interval or disable it with the negating command for the peer. By | |
1605 | default, the DelayOpenTimer is disabled. The timer interval may be set to a | |
1606 | duration of 1 to 240 seconds. | |
1607 | ||
4e853678 DS |
1608 | Displaying Information about Peers |
1609 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
1610 | ||
1611 | .. index:: show bgp <afi> <safi> neighbors WORD bestpath-routes [json] [wide] | |
1612 | .. clicmd:: show bgp <afi> <safi> neighbors WORD bestpath-routes [json] [wide] | |
1613 | ||
1614 | For the given neighbor, WORD, that is specified list the routes selected | |
1615 | by BGP as having the best path. | |
1616 | ||
8fcedbd2 | 1617 | .. _bgp-peer-filtering: |
42fc5d26 | 1618 | |
8fcedbd2 QY |
1619 | Peer Filtering |
1620 | ^^^^^^^^^^^^^^ | |
42fc5d26 | 1621 | |
c1a54c05 QY |
1622 | .. index:: neighbor PEER distribute-list NAME [in|out] |
1623 | .. clicmd:: neighbor PEER distribute-list NAME [in|out] | |
42fc5d26 | 1624 | |
c1a54c05 QY |
1625 | This command specifies a distribute-list for the peer. `direct` is |
1626 | ``in`` or ``out``. | |
42fc5d26 | 1627 | |
c3c5a71f | 1628 | .. index:: neighbor PEER prefix-list NAME [in|out] |
29adcd50 | 1629 | .. clicmd:: neighbor PEER prefix-list NAME [in|out] |
42fc5d26 | 1630 | |
c1a54c05 | 1631 | .. index:: neighbor PEER filter-list NAME [in|out] |
29adcd50 | 1632 | .. clicmd:: neighbor PEER filter-list NAME [in|out] |
42fc5d26 | 1633 | |
c1a54c05 QY |
1634 | .. index:: neighbor PEER route-map NAME [in|out] |
1635 | .. clicmd:: neighbor PEER route-map NAME [in|out] | |
42fc5d26 | 1636 | |
c1a54c05 | 1637 | Apply a route-map on the neighbor. `direct` must be `in` or `out`. |
42fc5d26 | 1638 | |
c3c5a71f | 1639 | .. index:: bgp route-reflector allow-outbound-policy |
29adcd50 | 1640 | .. clicmd:: bgp route-reflector allow-outbound-policy |
42fc5d26 | 1641 | |
c1a54c05 QY |
1642 | By default, attribute modification via route-map policy out is not reflected |
1643 | on reflected routes. This option allows the modifications to be reflected as | |
1644 | well. Once enabled, it affects all reflected routes. | |
42fc5d26 | 1645 | |
3d13052d | 1646 | .. index:: neighbor PEER sender-as-path-loop-detection |
583a9fd4 RZ |
1647 | .. clicmd:: [no] neighbor PEER sender-as-path-loop-detection |
1648 | ||
1649 | Enable the detection of sender side AS path loops and filter the | |
1650 | bad routes before they are sent. | |
1651 | ||
1652 | This setting is disabled by default. | |
1653 | ||
0efdf0fe | 1654 | .. _bgp-peer-group: |
42fc5d26 | 1655 | |
8fcedbd2 QY |
1656 | Peer Groups |
1657 | ^^^^^^^^^^^ | |
42fc5d26 | 1658 | |
199ad5c4 LB |
1659 | Peer groups are used to help improve scaling by generating the same |
1660 | update information to all members of a peer group. Note that this means | |
1661 | that the routes generated by a member of a peer group will be sent back | |
1662 | to that originating peer with the originator identifier attribute set to | |
1663 | indicated the originating peer. All peers not associated with a | |
1664 | specific peer group are treated as belonging to a default peer group, | |
1665 | and will share updates. | |
1666 | ||
c1a54c05 QY |
1667 | .. index:: neighbor WORD peer-group |
1668 | .. clicmd:: neighbor WORD peer-group | |
42fc5d26 | 1669 | |
c1a54c05 | 1670 | This command defines a new peer group. |
42fc5d26 | 1671 | |
d7b9898c DA |
1672 | .. index:: neighbor PEER peer-group PGNAME |
1673 | .. clicmd:: neighbor PEER peer-group PGNAME | |
c3c5a71f | 1674 | |
c1a54c05 | 1675 | This command bind specific peer to peer group WORD. |
42fc5d26 | 1676 | |
199ad5c4 LB |
1677 | .. index:: neighbor PEER solo |
1678 | .. clicmd:: neighbor PEER solo | |
1679 | ||
1680 | This command is used to indicate that routes advertised by the peer | |
1681 | should not be reflected back to the peer. This command only is only | |
1682 | meaningful when there is a single peer defined in the peer-group. | |
1683 | ||
8fcedbd2 QY |
1684 | Capability Negotiation |
1685 | ^^^^^^^^^^^^^^^^^^^^^^ | |
42fc5d26 | 1686 | |
8fcedbd2 QY |
1687 | .. index:: neighbor PEER strict-capability-match |
1688 | .. clicmd:: neighbor PEER strict-capability-match | |
42fc5d26 | 1689 | |
3d13052d | 1690 | .. index:: neighbor PEER strict-capability-match |
8fcedbd2 | 1691 | .. clicmd:: no neighbor PEER strict-capability-match |
c1a54c05 | 1692 | |
8fcedbd2 QY |
1693 | Strictly compares remote capabilities and local capabilities. If |
1694 | capabilities are different, send Unsupported Capability error then reset | |
1695 | connection. | |
42fc5d26 | 1696 | |
8fcedbd2 QY |
1697 | You may want to disable sending Capability Negotiation OPEN message optional |
1698 | parameter to the peer when remote peer does not implement Capability | |
1699 | Negotiation. Please use *dont-capability-negotiate* command to disable the | |
1700 | feature. | |
42fc5d26 | 1701 | |
3d13052d | 1702 | .. index:: neighbor PEER dont-capability-negotiate |
7cdc9530 | 1703 | .. clicmd:: [no] neighbor PEER dont-capability-negotiate |
42fc5d26 | 1704 | |
8fcedbd2 QY |
1705 | Suppress sending Capability Negotiation as OPEN message optional parameter |
1706 | to the peer. This command only affects the peer is configured other than | |
1707 | IPv4 unicast configuration. | |
42fc5d26 | 1708 | |
8fcedbd2 QY |
1709 | When remote peer does not have capability negotiation feature, remote peer |
1710 | will not send any capabilities at all. In that case, bgp configures the peer | |
1711 | with configured capabilities. | |
42fc5d26 | 1712 | |
8fcedbd2 QY |
1713 | You may prefer locally configured capabilities more than the negotiated |
1714 | capabilities even though remote peer sends capabilities. If the peer is | |
1715 | configured by *override-capability*, *bgpd* ignores received capabilities | |
1716 | then override negotiated capabilities with configured values. | |
42fc5d26 | 1717 | |
7cdc9530 DS |
1718 | Additionally the operator should be reminded that this feature fundamentally |
1719 | disables the ability to use widely deployed BGP features. BGP unnumbered, | |
1720 | hostname support, AS4, Addpath, Route Refresh, ORF, Dynamic Capabilities, | |
1721 | and graceful restart. | |
1722 | ||
8fcedbd2 QY |
1723 | .. index:: neighbor PEER override-capability |
1724 | .. clicmd:: neighbor PEER override-capability | |
42fc5d26 | 1725 | |
3d13052d | 1726 | .. index:: neighbor PEER override-capability |
8fcedbd2 | 1727 | .. clicmd:: no neighbor PEER override-capability |
c1a54c05 | 1728 | |
8fcedbd2 QY |
1729 | Override the result of Capability Negotiation with local configuration. |
1730 | Ignore remote peer's capability value. | |
42fc5d26 | 1731 | |
8fcedbd2 | 1732 | .. _bgp-as-path-access-lists: |
42fc5d26 | 1733 | |
8fcedbd2 QY |
1734 | AS Path Access Lists |
1735 | -------------------- | |
42fc5d26 QY |
1736 | |
1737 | AS path access list is user defined AS path. | |
1738 | ||
a64e0ee5 DA |
1739 | .. index:: bgp as-path access-list WORD permit|deny LINE |
1740 | .. clicmd:: bgp as-path access-list WORD permit|deny LINE | |
42fc5d26 | 1741 | |
c1a54c05 | 1742 | This command defines a new AS path access list. |
42fc5d26 | 1743 | |
3d13052d | 1744 | .. index:: bgp as-path access-list WORD |
a64e0ee5 | 1745 | .. clicmd:: no bgp as-path access-list WORD |
42fc5d26 | 1746 | |
3d13052d | 1747 | .. index:: bgp as-path access-list WORD permit|deny LINE |
a64e0ee5 | 1748 | .. clicmd:: no bgp as-path access-list WORD permit|deny LINE |
42fc5d26 | 1749 | |
125cec1a DA |
1750 | .. _bgp-bogon-filter-example: |
1751 | ||
1752 | Bogon ASN filter policy configuration example | |
1753 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
1754 | ||
1755 | .. code-block:: frr | |
1756 | ||
1757 | bgp as-path access-list 99 permit _0_ | |
1758 | bgp as-path access-list 99 permit _23456_ | |
1759 | bgp as-path access-list 99 permit _1310[0-6][0-9]_|_13107[0-1]_ | |
1760 | ||
8fcedbd2 | 1761 | .. _bgp-using-as-path-in-route-map: |
42fc5d26 QY |
1762 | |
1763 | Using AS Path in Route Map | |
1764 | -------------------------- | |
1765 | ||
3d13052d | 1766 | .. index:: match as-path WORD |
eb1f303d | 1767 | .. clicmd:: [no] match as-path WORD |
42fc5d26 | 1768 | |
eb1f303d DS |
1769 | For a given as-path, WORD, match it on the BGP as-path given for the prefix |
1770 | and if it matches do normal route-map actions. The no form of the command | |
1771 | removes this match from the route-map. | |
42fc5d26 | 1772 | |
3d13052d | 1773 | .. index:: set as-path prepend AS-PATH |
eb1f303d | 1774 | .. clicmd:: [no] set as-path prepend AS-PATH |
42fc5d26 | 1775 | |
eb1f303d DS |
1776 | Prepend the given string of AS numbers to the AS_PATH of the BGP path's NLRI. |
1777 | The no form of this command removes this set operation from the route-map. | |
42fc5d26 | 1778 | |
3d13052d | 1779 | .. index:: set as-path prepend last-as NUM |
eb1f303d | 1780 | .. clicmd:: [no] set as-path prepend last-as NUM |
c1a54c05 QY |
1781 | |
1782 | Prepend the existing last AS number (the leftmost ASN) to the AS_PATH. | |
eb1f303d | 1783 | The no form of this command removes this set operation from the route-map. |
42fc5d26 | 1784 | |
0efdf0fe | 1785 | .. _bgp-communities-attribute: |
42fc5d26 | 1786 | |
8fcedbd2 QY |
1787 | Communities Attribute |
1788 | --------------------- | |
42fc5d26 | 1789 | |
8fcedbd2 | 1790 | The BGP communities attribute is widely used for implementing policy routing. |
c1a54c05 QY |
1791 | Network operators can manipulate BGP communities attribute based on their |
1792 | network policy. BGP communities attribute is defined in :rfc:`1997` and | |
1793 | :rfc:`1998`. It is an optional transitive attribute, therefore local policy can | |
1794 | travel through different autonomous system. | |
1795 | ||
8fcedbd2 QY |
1796 | The communities attribute is a set of communities values. Each community value |
1797 | is 4 octet long. The following format is used to define the community value. | |
c1a54c05 | 1798 | |
8fcedbd2 | 1799 | ``AS:VAL`` |
c1a54c05 QY |
1800 | This format represents 4 octet communities value. ``AS`` is high order 2 |
1801 | octet in digit format. ``VAL`` is low order 2 octet in digit format. This | |
1802 | format is useful to define AS oriented policy value. For example, | |
1803 | ``7675:80`` can be used when AS 7675 wants to pass local policy value 80 to | |
1804 | neighboring peer. | |
1805 | ||
8fcedbd2 QY |
1806 | ``internet`` |
1807 | ``internet`` represents well-known communities value 0. | |
c1a54c05 | 1808 | |
cae770d3 C |
1809 | ``graceful-shutdown`` |
1810 | ``graceful-shutdown`` represents well-known communities value | |
1811 | ``GRACEFUL_SHUTDOWN`` ``0xFFFF0000`` ``65535:0``. :rfc:`8326` implements | |
1812 | the purpose Graceful BGP Session Shutdown to reduce the amount of | |
56f0bea7 | 1813 | lost traffic when taking BGP sessions down for maintenance. The use |
cae770d3 C |
1814 | of the community needs to be supported from your peers side to |
1815 | actually have any effect. | |
1816 | ||
1817 | ``accept-own`` | |
1818 | ``accept-own`` represents well-known communities value ``ACCEPT_OWN`` | |
1819 | ``0xFFFF0001`` ``65535:1``. :rfc:`7611` implements a way to signal | |
1820 | to a router to accept routes with a local nexthop address. This | |
1821 | can be the case when doing policing and having traffic having a | |
1822 | nexthop located in another VRF but still local interface to the | |
1823 | router. It is recommended to read the RFC for full details. | |
1824 | ||
1825 | ``route-filter-translated-v4`` | |
1826 | ``route-filter-translated-v4`` represents well-known communities value | |
1827 | ``ROUTE_FILTER_TRANSLATED_v4`` ``0xFFFF0002`` ``65535:2``. | |
1828 | ||
1829 | ``route-filter-v4`` | |
1830 | ``route-filter-v4`` represents well-known communities value | |
1831 | ``ROUTE_FILTER_v4`` ``0xFFFF0003`` ``65535:3``. | |
1832 | ||
1833 | ``route-filter-translated-v6`` | |
1834 | ``route-filter-translated-v6`` represents well-known communities value | |
1835 | ``ROUTE_FILTER_TRANSLATED_v6`` ``0xFFFF0004`` ``65535:4``. | |
1836 | ||
1837 | ``route-filter-v6`` | |
1838 | ``route-filter-v6`` represents well-known communities value | |
1839 | ``ROUTE_FILTER_v6`` ``0xFFFF0005`` ``65535:5``. | |
1840 | ||
1841 | ``llgr-stale`` | |
1842 | ``llgr-stale`` represents well-known communities value ``LLGR_STALE`` | |
1843 | ``0xFFFF0006`` ``65535:6``. | |
56f0bea7 | 1844 | Assigned and intended only for use with routers supporting the |
cae770d3 | 1845 | Long-lived Graceful Restart Capability as described in |
49606d58 | 1846 | [Draft-IETF-uttaro-idr-bgp-persistence]_. |
56f0bea7 | 1847 | Routers receiving routes with this community may (depending on |
cae770d3 C |
1848 | implementation) choose allow to reject or modify routes on the |
1849 | presence or absence of this community. | |
1850 | ||
1851 | ``no-llgr`` | |
1852 | ``no-llgr`` represents well-known communities value ``NO_LLGR`` | |
1853 | ``0xFFFF0007`` ``65535:7``. | |
56f0bea7 | 1854 | Assigned and intended only for use with routers supporting the |
cae770d3 | 1855 | Long-lived Graceful Restart Capability as described in |
49606d58 | 1856 | [Draft-IETF-uttaro-idr-bgp-persistence]_. |
56f0bea7 | 1857 | Routers receiving routes with this community may (depending on |
cae770d3 C |
1858 | implementation) choose allow to reject or modify routes on the |
1859 | presence or absence of this community. | |
1860 | ||
1861 | ``accept-own-nexthop`` | |
1862 | ``accept-own-nexthop`` represents well-known communities value | |
1863 | ``accept-own-nexthop`` ``0xFFFF0008`` ``65535:8``. | |
49606d58 | 1864 | [Draft-IETF-agrewal-idr-accept-own-nexthop]_ describes |
cae770d3 C |
1865 | how to tag and label VPN routes to be able to send traffic between VRFs |
1866 | via an internal layer 2 domain on the same PE device. Refer to | |
49606d58 | 1867 | [Draft-IETF-agrewal-idr-accept-own-nexthop]_ for full details. |
cae770d3 C |
1868 | |
1869 | ``blackhole`` | |
1870 | ``blackhole`` represents well-known communities value ``BLACKHOLE`` | |
1871 | ``0xFFFF029A`` ``65535:666``. :rfc:`7999` documents sending prefixes to | |
1872 | EBGP peers and upstream for the purpose of blackholing traffic. | |
1873 | Prefixes tagged with the this community should normally not be | |
1874 | re-advertised from neighbors of the originating network. It is | |
1875 | recommended upon receiving prefixes tagged with this community to | |
1876 | add ``NO_EXPORT`` and ``NO_ADVERTISE``. | |
1877 | ||
8fcedbd2 | 1878 | ``no-export`` |
c1a54c05 QY |
1879 | ``no-export`` represents well-known communities value ``NO_EXPORT`` |
1880 | ``0xFFFFFF01``. All routes carry this value must not be advertised to | |
1881 | outside a BGP confederation boundary. If neighboring BGP peer is part of BGP | |
1882 | confederation, the peer is considered as inside a BGP confederation | |
1883 | boundary, so the route will be announced to the peer. | |
1884 | ||
8fcedbd2 | 1885 | ``no-advertise`` |
c1a54c05 QY |
1886 | ``no-advertise`` represents well-known communities value ``NO_ADVERTISE`` |
1887 | ``0xFFFFFF02``. All routes carry this value must not be advertise to other | |
1888 | BGP peers. | |
1889 | ||
8fcedbd2 | 1890 | ``local-AS`` |
c1a54c05 QY |
1891 | ``local-AS`` represents well-known communities value ``NO_EXPORT_SUBCONFED`` |
1892 | ``0xFFFFFF03``. All routes carry this value must not be advertised to | |
1893 | external BGP peers. Even if the neighboring router is part of confederation, | |
1894 | it is considered as external BGP peer, so the route will not be announced to | |
1895 | the peer. | |
1896 | ||
cae770d3 C |
1897 | ``no-peer`` |
1898 | ``no-peer`` represents well-known communities value ``NOPEER`` | |
1899 | ``0xFFFFFF04`` ``65535:65284``. :rfc:`3765` is used to communicate to | |
1900 | another network how the originating network want the prefix propagated. | |
1901 | ||
aa9eafa4 QY |
1902 | When the communities attribute is received duplicate community values in the |
1903 | attribute are ignored and value is sorted in numerical order. | |
42fc5d26 | 1904 | |
49606d58 PG |
1905 | .. [Draft-IETF-uttaro-idr-bgp-persistence] <https://tools.ietf.org/id/draft-uttaro-idr-bgp-persistence-04.txt> |
1906 | .. [Draft-IETF-agrewal-idr-accept-own-nexthop] <https://tools.ietf.org/id/draft-agrewal-idr-accept-own-nexthop-00.txt> | |
1907 | ||
0efdf0fe | 1908 | .. _bgp-community-lists: |
42fc5d26 | 1909 | |
8fcedbd2 QY |
1910 | Community Lists |
1911 | ^^^^^^^^^^^^^^^ | |
aa9eafa4 QY |
1912 | Community lists are user defined lists of community attribute values. These |
1913 | lists can be used for matching or manipulating the communities attribute in | |
1914 | UPDATE messages. | |
42fc5d26 | 1915 | |
aa9eafa4 | 1916 | There are two types of community list: |
c1a54c05 | 1917 | |
aa9eafa4 | 1918 | standard |
56f0bea7 | 1919 | This type accepts an explicit value for the attribute. |
aa9eafa4 QY |
1920 | |
1921 | expanded | |
1922 | This type accepts a regular expression. Because the regex must be | |
1923 | interpreted on each use expanded community lists are slower than standard | |
1924 | lists. | |
42fc5d26 | 1925 | |
a64e0ee5 DA |
1926 | .. index:: bgp community-list standard NAME permit|deny COMMUNITY |
1927 | .. clicmd:: bgp community-list standard NAME permit|deny COMMUNITY | |
42fc5d26 | 1928 | |
aa9eafa4 QY |
1929 | This command defines a new standard community list. ``COMMUNITY`` is |
1930 | communities value. The ``COMMUNITY`` is compiled into community structure. | |
1931 | We can define multiple community list under same name. In that case match | |
1932 | will happen user defined order. Once the community list matches to | |
1933 | communities attribute in BGP updates it return permit or deny by the | |
1934 | community list definition. When there is no matched entry, deny will be | |
1935 | returned. When ``COMMUNITY`` is empty it matches to any routes. | |
42fc5d26 | 1936 | |
a64e0ee5 DA |
1937 | .. index:: bgp community-list expanded NAME permit|deny COMMUNITY |
1938 | .. clicmd:: bgp community-list expanded NAME permit|deny COMMUNITY | |
42fc5d26 | 1939 | |
aa9eafa4 QY |
1940 | This command defines a new expanded community list. ``COMMUNITY`` is a |
1941 | string expression of communities attribute. ``COMMUNITY`` can be a regular | |
1942 | expression (:ref:`bgp-regular-expressions`) to match the communities | |
47f47873 PG |
1943 | attribute in BGP updates. The expanded community is only used to filter, |
1944 | not `set` actions. | |
42fc5d26 | 1945 | |
aa9eafa4 QY |
1946 | .. deprecated:: 5.0 |
1947 | It is recommended to use the more explicit versions of this command. | |
42fc5d26 | 1948 | |
a64e0ee5 DA |
1949 | .. index:: bgp community-list NAME permit|deny COMMUNITY |
1950 | .. clicmd:: bgp community-list NAME permit|deny COMMUNITY | |
aa9eafa4 QY |
1951 | |
1952 | When the community list type is not specified, the community list type is | |
1953 | automatically detected. If ``COMMUNITY`` can be compiled into communities | |
1954 | attribute, the community list is defined as a standard community list. | |
1955 | Otherwise it is defined as an expanded community list. This feature is left | |
1956 | for backward compatibility. Use of this feature is not recommended. | |
42fc5d26 | 1957 | |
42fc5d26 | 1958 | |
3d13052d | 1959 | .. index:: bgp community-list [standard|expanded] NAME |
a64e0ee5 | 1960 | .. clicmd:: no bgp community-list [standard|expanded] NAME |
42fc5d26 | 1961 | |
aa9eafa4 QY |
1962 | Deletes the community list specified by ``NAME``. All community lists share |
1963 | the same namespace, so it's not necessary to specify ``standard`` or | |
1964 | ``expanded``; these modifiers are purely aesthetic. | |
42fc5d26 | 1965 | |
36dc43aa DA |
1966 | .. index:: show bgp community-list [NAME detail] |
1967 | .. clicmd:: show bgp community-list [NAME detail] | |
42fc5d26 | 1968 | |
aa9eafa4 QY |
1969 | Displays community list information. When ``NAME`` is specified the |
1970 | specified community list's information is shown. | |
c3c5a71f | 1971 | |
c1a54c05 | 1972 | :: |
76bd1499 | 1973 | |
a64e0ee5 | 1974 | # show bgp community-list |
c1a54c05 QY |
1975 | Named Community standard list CLIST |
1976 | permit 7675:80 7675:100 no-export | |
1977 | deny internet | |
1978 | Named Community expanded list EXPAND | |
1979 | permit : | |
76bd1499 | 1980 | |
36dc43aa | 1981 | # show bgp community-list CLIST detail |
c1a54c05 QY |
1982 | Named Community standard list CLIST |
1983 | permit 7675:80 7675:100 no-export | |
1984 | deny internet | |
42fc5d26 | 1985 | |
42fc5d26 | 1986 | |
8fcedbd2 | 1987 | .. _bgp-numbered-community-lists: |
42fc5d26 | 1988 | |
8fcedbd2 QY |
1989 | Numbered Community Lists |
1990 | ^^^^^^^^^^^^^^^^^^^^^^^^ | |
42fc5d26 QY |
1991 | |
1992 | When number is used for BGP community list name, the number has | |
c3c5a71f QY |
1993 | special meanings. Community list number in the range from 1 and 99 is |
1994 | standard community list. Community list number in the range from 100 | |
1995 | to 199 is expanded community list. These community lists are called | |
1996 | as numbered community lists. On the other hand normal community lists | |
42fc5d26 QY |
1997 | is called as named community lists. |
1998 | ||
a64e0ee5 DA |
1999 | .. index:: bgp community-list (1-99) permit|deny COMMUNITY |
2000 | .. clicmd:: bgp community-list (1-99) permit|deny COMMUNITY | |
42fc5d26 | 2001 | |
aa9eafa4 QY |
2002 | This command defines a new community list. The argument to (1-99) defines |
2003 | the list identifier. | |
42fc5d26 | 2004 | |
a64e0ee5 DA |
2005 | .. index:: bgp community-list (100-199) permit|deny COMMUNITY |
2006 | .. clicmd:: bgp community-list (100-199) permit|deny COMMUNITY | |
42fc5d26 | 2007 | |
aa9eafa4 QY |
2008 | This command defines a new expanded community list. The argument to |
2009 | (100-199) defines the list identifier. | |
42fc5d26 | 2010 | |
8fcedbd2 | 2011 | .. _bgp-using-communities-in-route-map: |
42fc5d26 | 2012 | |
8fcedbd2 QY |
2013 | Using Communities in Route Maps |
2014 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
42fc5d26 | 2015 | |
aa9eafa4 QY |
2016 | In :ref:`route-map` we can match on or set the BGP communities attribute. Using |
2017 | this feature network operator can implement their network policy based on BGP | |
2018 | communities attribute. | |
42fc5d26 | 2019 | |
b91bf5bd | 2020 | The following commands can be used in route maps: |
42fc5d26 | 2021 | |
aa9eafa4 QY |
2022 | .. index:: match community WORD exact-match [exact-match] |
2023 | .. clicmd:: match community WORD exact-match [exact-match] | |
42fc5d26 | 2024 | |
c1a54c05 QY |
2025 | This command perform match to BGP updates using community list WORD. When |
2026 | the one of BGP communities value match to the one of communities value in | |
d1e7591e | 2027 | community list, it is match. When `exact-match` keyword is specified, match |
c1a54c05 QY |
2028 | happen only when BGP updates have completely same communities value |
2029 | specified in the community list. | |
42fc5d26 | 2030 | |
aa9eafa4 QY |
2031 | .. index:: set community <none|COMMUNITY> additive |
2032 | .. clicmd:: set community <none|COMMUNITY> additive | |
42fc5d26 | 2033 | |
aa9eafa4 QY |
2034 | This command sets the community value in BGP updates. If the attribute is |
2035 | already configured, the newly provided value replaces the old one unless the | |
2036 | ``additive`` keyword is specified, in which case the new value is appended | |
2037 | to the existing value. | |
42fc5d26 | 2038 | |
aa9eafa4 QY |
2039 | If ``none`` is specified as the community value, the communities attribute |
2040 | is not sent. | |
42fc5d26 | 2041 | |
47f47873 PG |
2042 | It is not possible to set an expanded community list. |
2043 | ||
c1a54c05 | 2044 | .. index:: set comm-list WORD delete |
29adcd50 | 2045 | .. clicmd:: set comm-list WORD delete |
c1a54c05 | 2046 | |
aa9eafa4 QY |
2047 | This command remove communities value from BGP communities attribute. The |
2048 | ``word`` is community list name. When BGP route's communities value matches | |
2049 | to the community list ``word``, the communities value is removed. When all | |
2050 | of communities value is removed eventually, the BGP update's communities | |
2051 | attribute is completely removed. | |
42fc5d26 | 2052 | |
8fcedbd2 | 2053 | .. _bgp-communities-example: |
c1a54c05 | 2054 | |
8fcedbd2 QY |
2055 | Example Configuration |
2056 | ^^^^^^^^^^^^^^^^^^^^^ | |
9eb95b3b | 2057 | |
8fcedbd2 QY |
2058 | The following configuration is exemplary of the most typical usage of BGP |
2059 | communities attribute. In the example, AS 7675 provides an upstream Internet | |
2060 | connection to AS 100. When the following configuration exists in AS 7675, the | |
2061 | network operator of AS 100 can set local preference in AS 7675 network by | |
2062 | setting BGP communities attribute to the updates. | |
9eb95b3b QY |
2063 | |
2064 | .. code-block:: frr | |
c1a54c05 QY |
2065 | |
2066 | router bgp 7675 | |
2067 | neighbor 192.168.0.1 remote-as 100 | |
2068 | address-family ipv4 unicast | |
2069 | neighbor 192.168.0.1 route-map RMAP in | |
2070 | exit-address-family | |
2071 | ! | |
a64e0ee5 DA |
2072 | bgp community-list 70 permit 7675:70 |
2073 | bgp community-list 70 deny | |
2074 | bgp community-list 80 permit 7675:80 | |
2075 | bgp community-list 80 deny | |
2076 | bgp community-list 90 permit 7675:90 | |
2077 | bgp community-list 90 deny | |
c1a54c05 QY |
2078 | ! |
2079 | route-map RMAP permit 10 | |
2080 | match community 70 | |
2081 | set local-preference 70 | |
2082 | ! | |
2083 | route-map RMAP permit 20 | |
2084 | match community 80 | |
2085 | set local-preference 80 | |
2086 | ! | |
2087 | route-map RMAP permit 30 | |
2088 | match community 90 | |
2089 | set local-preference 90 | |
c3c5a71f | 2090 | |
42fc5d26 | 2091 | |
8fcedbd2 QY |
2092 | The following configuration announces ``10.0.0.0/8`` from AS 100 to AS 7675. |
2093 | The route has communities value ``7675:80`` so when above configuration exists | |
2094 | in AS 7675, the announced routes' local preference value will be set to 80. | |
9eb95b3b QY |
2095 | |
2096 | .. code-block:: frr | |
c1a54c05 QY |
2097 | |
2098 | router bgp 100 | |
2099 | network 10.0.0.0/8 | |
2100 | neighbor 192.168.0.2 remote-as 7675 | |
2101 | address-family ipv4 unicast | |
2102 | neighbor 192.168.0.2 route-map RMAP out | |
2103 | exit-address-family | |
2104 | ! | |
2105 | ip prefix-list PLIST permit 10.0.0.0/8 | |
2106 | ! | |
2107 | route-map RMAP permit 10 | |
2108 | match ip address prefix-list PLIST | |
2109 | set community 7675:80 | |
c3c5a71f | 2110 | |
42fc5d26 | 2111 | |
8fcedbd2 QY |
2112 | The following configuration is an example of BGP route filtering using |
2113 | communities attribute. This configuration only permit BGP routes which has BGP | |
2114 | communities value ``0:80`` or ``0:90``. The network operator can set special | |
2115 | internal communities value at BGP border router, then limit the BGP route | |
2116 | announcements into the internal network. | |
9eb95b3b QY |
2117 | |
2118 | .. code-block:: frr | |
42fc5d26 | 2119 | |
c1a54c05 QY |
2120 | router bgp 7675 |
2121 | neighbor 192.168.0.1 remote-as 100 | |
2122 | address-family ipv4 unicast | |
2123 | neighbor 192.168.0.1 route-map RMAP in | |
2124 | exit-address-family | |
2125 | ! | |
a64e0ee5 | 2126 | bgp community-list 1 permit 0:80 0:90 |
c1a54c05 QY |
2127 | ! |
2128 | route-map RMAP permit in | |
2129 | match community 1 | |
c3c5a71f | 2130 | |
42fc5d26 | 2131 | |
8fcedbd2 QY |
2132 | The following example filters BGP routes which have a community value of |
2133 | ``1:1``. When there is no match community-list returns ``deny``. To avoid | |
2134 | filtering all routes, a ``permit`` line is set at the end of the | |
2135 | community-list. | |
9eb95b3b QY |
2136 | |
2137 | .. code-block:: frr | |
42fc5d26 | 2138 | |
c1a54c05 QY |
2139 | router bgp 7675 |
2140 | neighbor 192.168.0.1 remote-as 100 | |
2141 | address-family ipv4 unicast | |
2142 | neighbor 192.168.0.1 route-map RMAP in | |
2143 | exit-address-family | |
2144 | ! | |
a64e0ee5 DA |
2145 | bgp community-list standard FILTER deny 1:1 |
2146 | bgp community-list standard FILTER permit | |
c1a54c05 QY |
2147 | ! |
2148 | route-map RMAP permit 10 | |
2149 | match community FILTER | |
c3c5a71f | 2150 | |
42fc5d26 | 2151 | |
8fcedbd2 QY |
2152 | The communities value keyword ``internet`` has special meanings in standard |
2153 | community lists. In the below example ``internet`` matches all BGP routes even | |
2154 | if the route does not have communities attribute at all. So community list | |
2155 | ``INTERNET`` is the same as ``FILTER`` in the previous example. | |
9eb95b3b QY |
2156 | |
2157 | .. code-block:: frr | |
42fc5d26 | 2158 | |
a64e0ee5 DA |
2159 | bgp community-list standard INTERNET deny 1:1 |
2160 | bgp community-list standard INTERNET permit internet | |
c3c5a71f | 2161 | |
42fc5d26 | 2162 | |
8fcedbd2 QY |
2163 | The following configuration is an example of communities value deletion. With |
2164 | this configuration the community values ``100:1`` and ``100:2`` are removed | |
2165 | from BGP updates. For communities value deletion, only ``permit`` | |
2166 | community-list is used. ``deny`` community-list is ignored. | |
9eb95b3b QY |
2167 | |
2168 | .. code-block:: frr | |
42fc5d26 | 2169 | |
c1a54c05 QY |
2170 | router bgp 7675 |
2171 | neighbor 192.168.0.1 remote-as 100 | |
2172 | address-family ipv4 unicast | |
2173 | neighbor 192.168.0.1 route-map RMAP in | |
2174 | exit-address-family | |
2175 | ! | |
a64e0ee5 | 2176 | bgp community-list standard DEL permit 100:1 100:2 |
c1a54c05 QY |
2177 | ! |
2178 | route-map RMAP permit 10 | |
2179 | set comm-list DEL delete | |
c3c5a71f | 2180 | |
42fc5d26 | 2181 | |
0efdf0fe | 2182 | .. _bgp-extended-communities-attribute: |
42fc5d26 | 2183 | |
8fcedbd2 QY |
2184 | Extended Communities Attribute |
2185 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
42fc5d26 | 2186 | |
c1a54c05 QY |
2187 | BGP extended communities attribute is introduced with MPLS VPN/BGP technology. |
2188 | MPLS VPN/BGP expands capability of network infrastructure to provide VPN | |
2189 | functionality. At the same time it requires a new framework for policy routing. | |
2190 | With BGP Extended Communities Attribute we can use Route Target or Site of | |
2191 | Origin for implementing network policy for MPLS VPN/BGP. | |
42fc5d26 | 2192 | |
c1a54c05 QY |
2193 | BGP Extended Communities Attribute is similar to BGP Communities Attribute. It |
2194 | is an optional transitive attribute. BGP Extended Communities Attribute can | |
2195 | carry multiple Extended Community value. Each Extended Community value is | |
2196 | eight octet length. | |
42fc5d26 | 2197 | |
c1a54c05 QY |
2198 | BGP Extended Communities Attribute provides an extended range compared with BGP |
2199 | Communities Attribute. Adding to that there is a type field in each value to | |
2200 | provides community space structure. | |
42fc5d26 | 2201 | |
c1a54c05 QY |
2202 | There are two format to define Extended Community value. One is AS based format |
2203 | the other is IP address based format. | |
42fc5d26 | 2204 | |
8fcedbd2 QY |
2205 | ``AS:VAL`` |
2206 | This is a format to define AS based Extended Community value. ``AS`` part | |
2207 | is 2 octets Global Administrator subfield in Extended Community value. | |
2208 | ``VAL`` part is 4 octets Local Administrator subfield. ``7675:100`` | |
2209 | represents AS 7675 policy value 100. | |
42fc5d26 | 2210 | |
8fcedbd2 | 2211 | ``IP-Address:VAL`` |
c1a54c05 | 2212 | This is a format to define IP address based Extended Community value. |
8fcedbd2 QY |
2213 | ``IP-Address`` part is 4 octets Global Administrator subfield. ``VAL`` part |
2214 | is 2 octets Local Administrator subfield. | |
42fc5d26 | 2215 | |
0efdf0fe | 2216 | .. _bgp-extended-community-lists: |
42fc5d26 | 2217 | |
8fcedbd2 QY |
2218 | Extended Community Lists |
2219 | ^^^^^^^^^^^^^^^^^^^^^^^^ | |
42fc5d26 | 2220 | |
a64e0ee5 DA |
2221 | .. index:: bgp extcommunity-list standard NAME permit|deny EXTCOMMUNITY |
2222 | .. clicmd:: bgp extcommunity-list standard NAME permit|deny EXTCOMMUNITY | |
42fc5d26 | 2223 | |
4da7fda3 QY |
2224 | This command defines a new standard extcommunity-list. `extcommunity` is |
2225 | extended communities value. The `extcommunity` is compiled into extended | |
2226 | community structure. We can define multiple extcommunity-list under same | |
2227 | name. In that case match will happen user defined order. Once the | |
2228 | extcommunity-list matches to extended communities attribute in BGP updates | |
2229 | it return permit or deny based upon the extcommunity-list definition. When | |
2230 | there is no matched entry, deny will be returned. When `extcommunity` is | |
2231 | empty it matches to any routes. | |
42fc5d26 | 2232 | |
a64e0ee5 DA |
2233 | .. index:: bgp extcommunity-list expanded NAME permit|deny LINE |
2234 | .. clicmd:: bgp extcommunity-list expanded NAME permit|deny LINE | |
42fc5d26 | 2235 | |
4da7fda3 QY |
2236 | This command defines a new expanded extcommunity-list. `line` is a string |
2237 | expression of extended communities attribute. `line` can be a regular | |
2238 | expression (:ref:`bgp-regular-expressions`) to match an extended communities | |
2239 | attribute in BGP updates. | |
42fc5d26 | 2240 | |
3d13052d | 2241 | .. index:: bgp extcommunity-list NAME |
a64e0ee5 | 2242 | .. clicmd:: no bgp extcommunity-list NAME |
42fc5d26 | 2243 | |
3d13052d | 2244 | .. index:: bgp extcommunity-list standard NAME |
a64e0ee5 | 2245 | .. clicmd:: no bgp extcommunity-list standard NAME |
42fc5d26 | 2246 | |
3d13052d | 2247 | .. index:: bgp extcommunity-list expanded NAME |
a64e0ee5 | 2248 | .. clicmd:: no bgp extcommunity-list expanded NAME |
42fc5d26 | 2249 | |
4da7fda3 QY |
2250 | These commands delete extended community lists specified by `name`. All of |
2251 | extended community lists shares a single name space. So extended community | |
d1e7591e | 2252 | lists can be removed simply specifying the name. |
42fc5d26 | 2253 | |
a64e0ee5 DA |
2254 | .. index:: show bgp extcommunity-list |
2255 | .. clicmd:: show bgp extcommunity-list | |
42fc5d26 | 2256 | |
36dc43aa DA |
2257 | .. index:: show bgp extcommunity-list NAME detail |
2258 | .. clicmd:: show bgp extcommunity-list NAME detail | |
c1a54c05 | 2259 | |
4da7fda3 | 2260 | This command displays current extcommunity-list information. When `name` is |
9eb95b3b | 2261 | specified the community list's information is shown.:: |
42fc5d26 | 2262 | |
a64e0ee5 | 2263 | # show bgp extcommunity-list |
c3c5a71f | 2264 | |
42fc5d26 | 2265 | |
0efdf0fe | 2266 | .. _bgp-extended-communities-in-route-map: |
42fc5d26 QY |
2267 | |
2268 | BGP Extended Communities in Route Map | |
8fcedbd2 | 2269 | """"""""""""""""""""""""""""""""""""" |
42fc5d26 | 2270 | |
c3c5a71f | 2271 | .. index:: match extcommunity WORD |
29adcd50 | 2272 | .. clicmd:: match extcommunity WORD |
42fc5d26 | 2273 | |
c1a54c05 | 2274 | .. index:: set extcommunity rt EXTCOMMUNITY |
29adcd50 | 2275 | .. clicmd:: set extcommunity rt EXTCOMMUNITY |
42fc5d26 | 2276 | |
c1a54c05 | 2277 | This command set Route Target value. |
42fc5d26 | 2278 | |
c1a54c05 | 2279 | .. index:: set extcommunity soo EXTCOMMUNITY |
29adcd50 | 2280 | .. clicmd:: set extcommunity soo EXTCOMMUNITY |
c1a54c05 QY |
2281 | |
2282 | This command set Site of Origin value. | |
42fc5d26 | 2283 | |
ed647ed2 | 2284 | .. index:: set extcommunity bandwidth <(1-25600) | cumulative | num-multipaths> [non-transitive] |
2285 | .. clicmd:: set extcommunity bandwidth <(1-25600) | cumulative | num-multipaths> [non-transitive] | |
2286 | ||
2287 | This command sets the BGP link-bandwidth extended community for the prefix | |
2288 | (best path) for which it is applied. The link-bandwidth can be specified as | |
2289 | an ``explicit value`` (specified in Mbps), or the router can be told to use | |
2290 | the ``cumulative bandwidth`` of all multipaths for the prefix or to compute | |
2291 | it based on the ``number of multipaths``. The link bandwidth extended | |
2292 | community is encoded as ``transitive`` unless the set command explicitly | |
2293 | configures it as ``non-transitive``. | |
2294 | ||
2295 | .. seealso:: :ref:`wecmp_linkbw` | |
47f47873 PG |
2296 | |
2297 | Note that the extended expanded community is only used for `match` rule, not for | |
2298 | `set` actions. | |
2299 | ||
0efdf0fe | 2300 | .. _bgp-large-communities-attribute: |
42fc5d26 | 2301 | |
8fcedbd2 QY |
2302 | Large Communities Attribute |
2303 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
42fc5d26 QY |
2304 | |
2305 | The BGP Large Communities attribute was introduced in Feb 2017 with | |
c1a54c05 | 2306 | :rfc:`8092`. |
42fc5d26 | 2307 | |
8fcedbd2 QY |
2308 | The BGP Large Communities Attribute is similar to the BGP Communities Attribute |
2309 | except that it has 3 components instead of two and each of which are 4 octets | |
2310 | in length. Large Communities bring additional functionality and convenience | |
2311 | over traditional communities, specifically the fact that the ``GLOBAL`` part | |
2312 | below is now 4 octets wide allowing seamless use in networks using 4-byte ASNs. | |
2313 | ||
2314 | ``GLOBAL:LOCAL1:LOCAL2`` | |
2315 | This is the format to define Large Community values. Referencing :rfc:`8195` | |
2316 | the values are commonly referred to as follows: | |
2317 | ||
2318 | - The ``GLOBAL`` part is a 4 octet Global Administrator field, commonly used | |
2319 | as the operators AS number. | |
2320 | - The ``LOCAL1`` part is a 4 octet Local Data Part 1 subfield referred to as | |
2321 | a function. | |
2322 | - The ``LOCAL2`` part is a 4 octet Local Data Part 2 field and referred to | |
2323 | as the parameter subfield. | |
2324 | ||
2325 | As an example, ``65551:1:10`` represents AS 65551 function 1 and parameter | |
2326 | 10. The referenced RFC above gives some guidelines on recommended usage. | |
42fc5d26 | 2327 | |
0efdf0fe | 2328 | .. _bgp-large-community-lists: |
42fc5d26 | 2329 | |
8fcedbd2 QY |
2330 | Large Community Lists |
2331 | """"""""""""""""""""" | |
42fc5d26 QY |
2332 | |
2333 | Two types of large community lists are supported, namely `standard` and | |
2334 | `expanded`. | |
2335 | ||
a64e0ee5 DA |
2336 | .. index:: bgp large-community-list standard NAME permit|deny LARGE-COMMUNITY |
2337 | .. clicmd:: bgp large-community-list standard NAME permit|deny LARGE-COMMUNITY | |
42fc5d26 | 2338 | |
4da7fda3 QY |
2339 | This command defines a new standard large-community-list. `large-community` |
2340 | is the Large Community value. We can add multiple large communities under | |
2341 | same name. In that case the match will happen in the user defined order. | |
2342 | Once the large-community-list matches the Large Communities attribute in BGP | |
2343 | updates it will return permit or deny based upon the large-community-list | |
2344 | definition. When there is no matched entry, a deny will be returned. When | |
2345 | `large-community` is empty it matches any routes. | |
42fc5d26 | 2346 | |
a64e0ee5 DA |
2347 | .. index:: bgp large-community-list expanded NAME permit|deny LINE |
2348 | .. clicmd:: bgp large-community-list expanded NAME permit|deny LINE | |
42fc5d26 | 2349 | |
4da7fda3 QY |
2350 | This command defines a new expanded large-community-list. Where `line` is a |
2351 | string matching expression, it will be compared to the entire Large | |
2352 | Communities attribute as a string, with each large-community in order from | |
2353 | lowest to highest. `line` can also be a regular expression which matches | |
2354 | this Large Community attribute. | |
42fc5d26 | 2355 | |
3d13052d | 2356 | .. index:: bgp large-community-list NAME |
a64e0ee5 | 2357 | .. clicmd:: no bgp large-community-list NAME |
42fc5d26 | 2358 | |
3d13052d | 2359 | .. index:: bgp large-community-list standard NAME |
a64e0ee5 | 2360 | .. clicmd:: no bgp large-community-list standard NAME |
42fc5d26 | 2361 | |
3d13052d | 2362 | .. index:: bgp large-community-list expanded NAME |
a64e0ee5 | 2363 | .. clicmd:: no bgp large-community-list expanded NAME |
42fc5d26 | 2364 | |
4da7fda3 QY |
2365 | These commands delete Large Community lists specified by `name`. All Large |
2366 | Community lists share a single namespace. This means Large Community lists | |
2367 | can be removed by simply specifying the name. | |
42fc5d26 | 2368 | |
a64e0ee5 DA |
2369 | .. index:: show bgp large-community-list |
2370 | .. clicmd:: show bgp large-community-list | |
42fc5d26 | 2371 | |
36dc43aa DA |
2372 | .. index:: show bgp large-community-list NAME detail |
2373 | .. clicmd:: show bgp large-community-list NAME detail | |
42fc5d26 | 2374 | |
c1a54c05 QY |
2375 | This command display current large-community-list information. When |
2376 | `name` is specified the community list information is shown. | |
42fc5d26 | 2377 | |
c1a54c05 | 2378 | .. index:: show ip bgp large-community-info |
29adcd50 | 2379 | .. clicmd:: show ip bgp large-community-info |
c1a54c05 QY |
2380 | |
2381 | This command displays the current large communities in use. | |
42fc5d26 | 2382 | |
0efdf0fe | 2383 | .. _bgp-large-communities-in-route-map: |
42fc5d26 | 2384 | |
8fcedbd2 QY |
2385 | Large Communities in Route Map |
2386 | """""""""""""""""""""""""""""" | |
42fc5d26 | 2387 | |
03ff9a14 | 2388 | .. index:: match large-community LINE [exact-match] |
2389 | .. clicmd:: match large-community LINE [exact-match] | |
42fc5d26 | 2390 | |
4da7fda3 QY |
2391 | Where `line` can be a simple string to match, or a regular expression. It |
2392 | is very important to note that this match occurs on the entire | |
c1a54c05 | 2393 | large-community string as a whole, where each large-community is ordered |
03ff9a14 | 2394 | from lowest to highest. When `exact-match` keyword is specified, match |
2395 | happen only when BGP updates have completely same large communities value | |
2396 | specified in the large community list. | |
42fc5d26 | 2397 | |
c1a54c05 | 2398 | .. index:: set large-community LARGE-COMMUNITY |
29adcd50 | 2399 | .. clicmd:: set large-community LARGE-COMMUNITY |
42fc5d26 | 2400 | |
c1a54c05 | 2401 | .. index:: set large-community LARGE-COMMUNITY LARGE-COMMUNITY |
29adcd50 | 2402 | .. clicmd:: set large-community LARGE-COMMUNITY LARGE-COMMUNITY |
42fc5d26 | 2403 | |
c1a54c05 | 2404 | .. index:: set large-community LARGE-COMMUNITY additive |
29adcd50 | 2405 | .. clicmd:: set large-community LARGE-COMMUNITY additive |
c1a54c05 QY |
2406 | |
2407 | These commands are used for setting large-community values. The first | |
2408 | command will overwrite any large-communities currently present. | |
2409 | The second specifies two large-communities, which overwrites the current | |
2410 | large-community list. The third will add a large-community value without | |
2411 | overwriting other values. Multiple large-community values can be specified. | |
42fc5d26 | 2412 | |
47f47873 PG |
2413 | Note that the large expanded community is only used for `match` rule, not for |
2414 | `set` actions. | |
b572f826 | 2415 | |
c8a5e5e1 | 2416 | .. _bgp-l3vpn-vrfs: |
b572f826 | 2417 | |
c8a5e5e1 QY |
2418 | L3VPN VRFs |
2419 | ---------- | |
b572f826 | 2420 | |
c8a5e5e1 QY |
2421 | *bgpd* supports :abbr:`L3VPN (Layer 3 Virtual Private Networks)` :abbr:`VRFs |
2422 | (Virtual Routing and Forwarding)` for IPv4 :rfc:`4364` and IPv6 :rfc:`4659`. | |
2423 | L3VPN routes, and their associated VRF MPLS labels, can be distributed to VPN | |
2424 | SAFI neighbors in the *default*, i.e., non VRF, BGP instance. VRF MPLS labels | |
2425 | are reached using *core* MPLS labels which are distributed using LDP or BGP | |
2426 | labeled unicast. *bgpd* also supports inter-VRF route leaking. | |
b572f826 | 2427 | |
b572f826 | 2428 | |
c8a5e5e1 | 2429 | .. _bgp-vrf-route-leaking: |
8fcedbd2 QY |
2430 | |
2431 | VRF Route Leaking | |
c8a5e5e1 | 2432 | ----------------- |
8fcedbd2 QY |
2433 | |
2434 | BGP routes may be leaked (i.e. copied) between a unicast VRF RIB and the VPN | |
f90115c5 LB |
2435 | SAFI RIB of the default VRF for use in MPLS-based L3VPNs. Unicast routes may |
2436 | also be leaked between any VRFs (including the unicast RIB of the default BGP | |
2437 | instanced). A shortcut syntax is also available for specifying leaking from one | |
2438 | VRF to another VRF using the default instance's VPN RIB as the intemediary. A | |
2439 | common application of the VRF-VRF feature is to connect a customer's private | |
8fcedbd2 QY |
2440 | routing domain to a provider's VPN service. Leaking is configured from the |
2441 | point of view of an individual VRF: ``import`` refers to routes leaked from VPN | |
2442 | to a unicast VRF, whereas ``export`` refers to routes leaked from a unicast VRF | |
2443 | to VPN. | |
2444 | ||
2445 | Required parameters | |
c8a5e5e1 | 2446 | ^^^^^^^^^^^^^^^^^^^ |
b572f826 | 2447 | |
4da7fda3 QY |
2448 | Routes exported from a unicast VRF to the VPN RIB must be augmented by two |
2449 | parameters: | |
2450 | ||
2451 | - an :abbr:`RD (Route Distinguisher)` | |
2452 | - an :abbr:`RTLIST (Route-target List)` | |
2453 | ||
2454 | Configuration for these exported routes must, at a minimum, specify these two | |
2455 | parameters. | |
2456 | ||
2457 | Routes imported from the VPN RIB to a unicast VRF are selected according to | |
2458 | their RTLISTs. Routes whose RTLIST contains at least one route-target in | |
2459 | common with the configured import RTLIST are leaked. Configuration for these | |
2460 | imported routes must specify an RTLIST to be matched. | |
2461 | ||
2462 | The RD, which carries no semantic value, is intended to make the route unique | |
2463 | in the VPN RIB among all routes of its prefix that originate from all the | |
2464 | customers and sites that are attached to the provider's VPN service. | |
2465 | Accordingly, each site of each customer is typically assigned an RD that is | |
2466 | unique across the entire provider network. | |
2467 | ||
2468 | The RTLIST is a set of route-target extended community values whose purpose is | |
2469 | to specify route-leaking policy. Typically, a customer is assigned a single | |
2470 | route-target value for import and export to be used at all customer sites. This | |
2471 | configuration specifies a simple topology wherein a customer has a single | |
2472 | routing domain which is shared across all its sites. More complex routing | |
2473 | topologies are possible through use of additional route-targets to augment the | |
2474 | leaking of sets of routes in various ways. | |
b572f826 | 2475 | |
e967a1d0 DS |
2476 | When using the shortcut syntax for vrf-to-vrf leaking, the RD and RT are |
2477 | auto-derived. | |
fb3d9f3e | 2478 | |
8fcedbd2 | 2479 | General configuration |
c8a5e5e1 | 2480 | ^^^^^^^^^^^^^^^^^^^^^ |
b572f826 | 2481 | |
f90115c5 | 2482 | Configuration of route leaking between a unicast VRF RIB and the VPN SAFI RIB |
4da7fda3 QY |
2483 | of the default VRF is accomplished via commands in the context of a VRF |
2484 | address-family: | |
b572f826 PZ |
2485 | |
2486 | .. index:: rd vpn export AS:NN|IP:nn | |
2487 | .. clicmd:: rd vpn export AS:NN|IP:nn | |
2488 | ||
4da7fda3 QY |
2489 | Specifies the route distinguisher to be added to a route exported from the |
2490 | current unicast VRF to VPN. | |
b572f826 | 2491 | |
3d13052d | 2492 | .. index:: rd vpn export [AS:NN|IP:nn] |
b572f826 PZ |
2493 | .. clicmd:: no rd vpn export [AS:NN|IP:nn] |
2494 | ||
2495 | Deletes any previously-configured export route distinguisher. | |
2496 | ||
2497 | .. index:: rt vpn import|export|both RTLIST... | |
2498 | .. clicmd:: rt vpn import|export|both RTLIST... | |
2499 | ||
4da7fda3 QY |
2500 | Specifies the route-target list to be attached to a route (export) or the |
2501 | route-target list to match against (import) when exporting/importing between | |
2502 | the current unicast VRF and VPN. | |
b572f826 | 2503 | |
4da7fda3 QY |
2504 | The RTLIST is a space-separated list of route-targets, which are BGP |
2505 | extended community values as described in | |
b572f826 PZ |
2506 | :ref:`bgp-extended-communities-attribute`. |
2507 | ||
3d13052d | 2508 | .. index:: rt vpn import|export|both [RTLIST...] |
b572f826 PZ |
2509 | .. clicmd:: no rt vpn import|export|both [RTLIST...] |
2510 | ||
2511 | Deletes any previously-configured import or export route-target list. | |
2512 | ||
e70e9f8e PZ |
2513 | .. index:: label vpn export (0..1048575)|auto |
2514 | .. clicmd:: label vpn export (0..1048575)|auto | |
b572f826 | 2515 | |
8a2124f7 | 2516 | Enables an MPLS label to be attached to a route exported from the current |
2517 | unicast VRF to VPN. If the value specified is ``auto``, the label value is | |
2518 | automatically assigned from a pool maintained by the Zebra daemon. If Zebra | |
2519 | is not running, or if this command is not configured, automatic label | |
2520 | assignment will not complete, which will block corresponding route export. | |
b572f826 | 2521 | |
3d13052d | 2522 | .. index:: label vpn export [(0..1048575)|auto] |
e70e9f8e | 2523 | .. clicmd:: no label vpn export [(0..1048575)|auto] |
b572f826 PZ |
2524 | |
2525 | Deletes any previously-configured export label. | |
2526 | ||
2527 | .. index:: nexthop vpn export A.B.C.D|X:X::X:X | |
2528 | .. clicmd:: nexthop vpn export A.B.C.D|X:X::X:X | |
2529 | ||
4da7fda3 QY |
2530 | Specifies an optional nexthop value to be assigned to a route exported from |
2531 | the current unicast VRF to VPN. If left unspecified, the nexthop will be set | |
2532 | to 0.0.0.0 or 0:0::0:0 (self). | |
b572f826 | 2533 | |
3d13052d | 2534 | .. index:: nexthop vpn export [A.B.C.D|X:X::X:X] |
b572f826 PZ |
2535 | .. clicmd:: no nexthop vpn export [A.B.C.D|X:X::X:X] |
2536 | ||
2537 | Deletes any previously-configured export nexthop. | |
2538 | ||
2539 | .. index:: route-map vpn import|export MAP | |
2540 | .. clicmd:: route-map vpn import|export MAP | |
2541 | ||
4da7fda3 | 2542 | Specifies an optional route-map to be applied to routes imported or exported |
d1e7591e | 2543 | between the current unicast VRF and VPN. |
b572f826 | 2544 | |
3d13052d | 2545 | .. index:: route-map vpn import|export [MAP] |
b572f826 PZ |
2546 | .. clicmd:: no route-map vpn import|export [MAP] |
2547 | ||
2548 | Deletes any previously-configured import or export route-map. | |
2549 | ||
2550 | .. index:: import|export vpn | |
2551 | .. clicmd:: import|export vpn | |
2552 | ||
d1e7591e | 2553 | Enables import or export of routes between the current unicast VRF and VPN. |
b572f826 | 2554 | |
3d13052d | 2555 | .. index:: import|export vpn |
b572f826 PZ |
2556 | .. clicmd:: no import|export vpn |
2557 | ||
d1e7591e | 2558 | Disables import or export of routes between the current unicast VRF and VPN. |
b572f826 | 2559 | |
fb3d9f3e DS |
2560 | .. index:: import vrf VRFNAME |
2561 | .. clicmd:: import vrf VRFNAME | |
2562 | ||
e967a1d0 DS |
2563 | Shortcut syntax for specifying automatic leaking from vrf VRFNAME to |
2564 | the current VRF using the VPN RIB as intermediary. The RD and RT | |
2565 | are auto derived and should not be specified explicitly for either the | |
2566 | source or destination VRF's. | |
2567 | ||
2568 | This shortcut syntax mode is not compatible with the explicit | |
2569 | `import vpn` and `export vpn` statements for the two VRF's involved. | |
2570 | The CLI will disallow attempts to configure incompatible leaking | |
2571 | modes. | |
fb3d9f3e | 2572 | |
3d13052d | 2573 | .. index:: import vrf VRFNAME |
fb3d9f3e DS |
2574 | .. clicmd:: no import vrf VRFNAME |
2575 | ||
e967a1d0 DS |
2576 | Disables automatic leaking from vrf VRFNAME to the current VRF using |
2577 | the VPN RIB as intermediary. | |
b572f826 | 2578 | |
42fc5d26 | 2579 | |
b6c34e85 CS |
2580 | .. _bgp-evpn: |
2581 | ||
2582 | Ethernet Virtual Network - EVPN | |
2583 | ------------------------------- | |
2584 | ||
2585 | .. _bgp-evpn-advertise-pip: | |
2586 | ||
2587 | EVPN advertise-PIP | |
2588 | ^^^^^^^^^^^^^^^^^^ | |
2589 | ||
2590 | In a EVPN symmetric routing MLAG deployment, all EVPN routes advertised | |
2591 | with anycast-IP as next-hop IP and anycast MAC as the Router MAC (RMAC - in | |
2592 | BGP EVPN Extended-Community). | |
2593 | EVPN picks up the next-hop IP from the VxLAN interface's local tunnel IP and | |
2594 | the RMAC is obtained from the MAC of the L3VNI's SVI interface. | |
2595 | Note: Next-hop IP is used for EVPN routes whether symmetric routing is | |
2596 | deployed or not but the RMAC is only relevant for symmetric routing scenario. | |
2597 | ||
2598 | Current behavior is not ideal for Prefix (type-5) and self (type-2) | |
2599 | routes. This is because the traffic from remote VTEPs routed sub optimally | |
2600 | if they land on the system where the route does not belong. | |
2601 | ||
2602 | The advertise-pip feature advertises Prefix (type-5) and self (type-2) | |
2603 | routes with system's individual (primary) IP as the next-hop and individual | |
2604 | (system) MAC as Router-MAC (RMAC), while leaving the behavior unchanged for | |
2605 | other EVPN routes. | |
2606 | ||
2607 | To support this feature there needs to have ability to co-exist a | |
2608 | (system-MAC, system-IP) pair with a (anycast-MAC, anycast-IP) pair with the | |
2609 | ability to terminate VxLAN-encapsulated packets received for either pair on | |
2610 | the same L3VNI (i.e associated VLAN). This capability is need per tenant | |
2611 | VRF instance. | |
2612 | ||
2613 | To derive the system-MAC and the anycast MAC, there needs to have a | |
2614 | separate/additional MAC-VLAN interface corresponding to L3VNI’s SVI. | |
2615 | The SVI interface’s MAC address can be interpreted as system-MAC | |
2616 | and MAC-VLAN interface's MAC as anycast MAC. | |
2617 | ||
2618 | To derive system-IP and anycast-IP, the default BGP instance's router-id is used | |
2619 | as system-IP and the VxLAN interface’s local tunnel IP as the anycast-IP. | |
2620 | ||
2621 | User has an option to configure the system-IP and/or system-MAC value if the | |
2622 | auto derived value is not preferred. | |
2623 | ||
2624 | Note: By default, advertise-pip feature is enabled and user has an option to | |
2625 | disable the feature via configuration CLI. Once the feature is disable under | |
2626 | bgp vrf instance or MAC-VLAN interface is not configured, all the routes follow | |
2627 | the same behavior of using same next-hop and RMAC values. | |
2628 | ||
3d13052d | 2629 | .. index:: advertise-pip [ip <addr> [mac <addr>]] |
b6c34e85 CS |
2630 | .. clicmd:: [no] advertise-pip [ip <addr> [mac <addr>]] |
2631 | ||
2632 | Enables or disables advertise-pip feature, specifiy system-IP and/or system-MAC | |
2633 | parameters. | |
2634 | ||
77457939 AK |
2635 | EVPN Multihoming |
2636 | ^^^^^^^^^^^^^^^^ | |
2637 | ||
2638 | All-Active Multihoming is used for redundancy and load sharing. Servers | |
2639 | are attached to two or more PEs and the links are bonded (link-aggregation). | |
2640 | This group of server links is referred to as an Ethernet Segment. | |
2641 | ||
2642 | Ethernet Segments | |
2643 | """"""""""""""""" | |
2644 | An Ethernet Segment can be configured by specifying a system-MAC and a | |
2645 | local discriminatior against the bond interface on the PE (via zebra) - | |
2646 | ||
3d13052d | 2647 | .. index:: evpn mh es-id [(1-16777215)$es_lid] |
77457939 AK |
2648 | .. clicmd:: [no] evpn mh es-id [(1-16777215)$es_lid] |
2649 | ||
3d13052d | 2650 | .. index:: evpn mh es-sys-mac [X:X:X:X:X:X$mac] |
77457939 AK |
2651 | .. clicmd:: [no$no] evpn mh es-sys-mac [X:X:X:X:X:X$mac] |
2652 | ||
2653 | The sys-mac and local discriminator are used for generating a 10-byte, | |
2654 | Type-3 Ethernet Segment ID. | |
2655 | ||
2656 | Type-1 (EAS-per-ES and EAD-per-EVI) routes are used to advertise the locally | |
2657 | attached ESs and to learn off remote ESs in the network. Local Type-2/MAC-IP | |
2658 | routes are also advertised with a destination ESI allowing for MAC-IP syncing | |
2659 | between Ethernet Segment peers. | |
2660 | Reference: RFC 7432, RFC 8365 | |
2661 | ||
2662 | EVPN-MH is intended as a replacement for MLAG or Anycast VTEPs. In | |
2663 | multihoming each PE has an unique VTEP address which requires the introduction | |
2664 | of a new dataplane construct, MAC-ECMP. Here a MAC/FDB entry can point to a | |
2665 | list of remote PEs/VTEPs. | |
2666 | ||
2667 | BUM handling | |
2668 | """""""""""" | |
2669 | Type-4 (ESR) routes are used for Designated Forwarder (DF) election. DFs | |
2670 | forward BUM traffic received via the overlay network. This implementation | |
2671 | uses a preference based DF election specified by draft-ietf-bess-evpn-pref-df. | |
2672 | The DF preference is configurable per-ES (via zebra) - | |
2673 | ||
3d13052d | 2674 | .. index:: evpn mh es-df-pref [(1-16777215)$df_pref] |
77457939 AK |
2675 | .. clicmd:: [no] evpn mh es-df-pref [(1-16777215)$df_pref] |
2676 | ||
2677 | BUM traffic is rxed via the overlay by all PEs attached to a server but | |
2678 | only the DF can forward the de-capsulated traffic to the access port. To | |
2679 | accomodate that non-DF filters are installed in the dataplane to drop | |
2680 | the traffic. | |
2681 | ||
2682 | Similarly traffic received from ES peers via the overlay cannot be forwarded | |
2683 | to the server. This is split-horizon-filtering with local bias. | |
2684 | ||
2685 | Fast failover | |
2686 | """"""""""""" | |
2687 | As the primary purpose of EVPN-MH is redundancy keeping the failover efficient | |
2688 | is a recurring theme in the implementation. Following sub-features have | |
2689 | been introduced for the express purpose of efficient ES failovers. | |
2690 | ||
2691 | - Layer-2 Nexthop Groups and MAC-ECMP via L2NHG. | |
2692 | ||
2693 | - Host routes (for symmetric IRB) via L3NHG. | |
2694 | On dataplanes that support layer3 nexthop groups the feature can be turned | |
2695 | on via the following BGP config - | |
2696 | ||
3d13052d | 2697 | .. index:: use-es-l3nhg |
77457939 AK |
2698 | .. clicmd:: [no$no] use-es-l3nhg |
2699 | ||
2700 | - Local ES (MAC/Neigh) failover via ES-redirect. | |
2701 | On dataplanes that do not have support for ES-redirect the feature can be | |
2702 | turned off via the following zebra config - | |
2703 | ||
3d13052d | 2704 | .. index:: evpn mh redirect-off |
77457939 AK |
2705 | .. clicmd:: [no$no] evpn mh redirect-off |
2706 | ||
2707 | Uplink/Core tracking | |
2708 | """""""""""""""""""" | |
2709 | When all the underlay links go down the PE no longer has access to the VxLAN | |
2710 | +overlay. To prevent blackholing of traffic the server/ES links are | |
2711 | protodowned on the PE. A link can be setup for uplink tracking via the | |
2712 | following zebra configuration - | |
2713 | ||
3d13052d | 2714 | .. index:: evpn mh uplink |
77457939 AK |
2715 | .. clicmd:: [no] evpn mh uplink |
2716 | ||
2717 | Proxy advertisements | |
2718 | """""""""""""""""""" | |
2719 | To handle hitless upgrades support for proxy advertisement has been added | |
2720 | as specified by draft-rbickhart-evpn-ip-mac-proxy-adv. This allows a PE | |
2721 | (say PE1) to proxy advertise a MAC-IP rxed from an ES peer (say PE2). When | |
2722 | the ES peer (PE2) goes down PE1 continues to advertise hosts learnt from PE2 | |
2723 | for a holdtime during which it attempts to establish local reachability of | |
2724 | the host. This holdtime is configurable via the following zebra commands - | |
2725 | ||
3d13052d | 2726 | .. index:: evpn mh neigh-holdtime (0-86400)$duration |
77457939 AK |
2727 | .. clicmd:: [no$no] evpn mh neigh-holdtime (0-86400)$duration |
2728 | ||
3d13052d | 2729 | .. index:: evpn mh mac-holdtime (0-86400)$duration |
77457939 AK |
2730 | .. clicmd:: [no$no] evpn mh mac-holdtime (0-86400)$duration |
2731 | ||
2732 | Startup delay | |
2733 | """"""""""""" | |
2734 | When a switch is rebooted we wait for a brief period to allow the underlay | |
2735 | and EVPN network to converge before enabling the ESs. For this duration the | |
2736 | ES bonds are held protodown. The startup delay is configurable via the | |
2737 | following zebra command - | |
2738 | ||
3d13052d | 2739 | .. index:: evpn mh startup-delay(0-3600)$duration |
77457939 AK |
2740 | .. clicmd:: [no] evpn mh startup-delay(0-3600)$duration |
2741 | ||
ee9d0f09 PG |
2742 | +Support with VRF network namespace backend |
2743 | +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
2744 | It is possible to separate overlay networks contained in VXLAN interfaces from | |
2745 | underlay networks by using VRFs. VRF-lite and VRF-netns backends can be used for | |
2746 | that. In the latter case, it is necessary to set both bridge and vxlan interface | |
2747 | in the same network namespace, as below example illustrates: | |
2748 | ||
2749 | .. code-block:: shell | |
2750 | ||
2751 | # linux shell | |
2752 | ip netns add vrf1 | |
2753 | ip link add name vxlan101 type vxlan id 101 dstport 4789 dev eth0 local 10.1.1.1 | |
2754 | ip link set dev vxlan101 netns vrf1 | |
2755 | ip netns exec vrf1 ip link set dev lo up | |
2756 | ip netns exec vrf1 brctl addbr bridge101 | |
2757 | ip netns exec vrf1 brctl addif bridge101 vxlan101 | |
2758 | ||
2759 | This makes it possible to separate not only layer 3 networks like VRF-lite networks. | |
2760 | Also, VRF netns based make possible to separate layer 2 networks on separate VRF | |
2761 | instances. | |
89b97c33 | 2762 | |
7f7940e6 MK |
2763 | .. _bgp-conditional-advertisement: |
2764 | ||
2765 | BGP Conditional Advertisement | |
2766 | ----------------------------- | |
2767 | The BGP conditional advertisement feature uses the ``non-exist-map`` or the | |
2768 | ``exist-map`` and the ``advertise-map`` keywords of the neighbor advertise-map | |
2769 | command in order to track routes by the route prefix. | |
2770 | ||
2771 | ``non-exist-map`` | |
2772 | 1. If a route prefix is not present in the output of non-exist-map command, | |
2773 | then advertise the route specified by the advertise-map command. | |
2774 | ||
2775 | 2. If a route prefix is present in the output of non-exist-map command, | |
2776 | then do not advertise the route specified by the addvertise-map command. | |
2777 | ||
2778 | ``exist-map`` | |
2779 | 1. If a route prefix is present in the output of exist-map command, | |
2780 | then advertise the route specified by the advertise-map command. | |
2781 | ||
2782 | 2. If a route prefix is not present in the output of exist-map command, | |
2783 | then do not advertise the route specified by the advertise-map command. | |
2784 | ||
2785 | This feature is useful when some prefixes are advertised to one of its peers | |
2786 | only if the information from the other peer is not present (due to failure in | |
2787 | peering session or partial reachability etc). | |
2788 | ||
2789 | The conditional BGP announcements are sent in addition to the normal | |
2790 | announcements that a BGP router sends to its peer. | |
2791 | ||
2792 | The conditional advertisement process is triggered by the BGP scanner process, | |
2793 | which runs every 60 seconds. This means that the maximum time for the conditional | |
2794 | advertisement to take effect is 60 seconds. The conditional advertisement can take | |
2795 | effect depending on when the tracked route is removed from the BGP table and | |
2796 | when the next instance of the BGP scanner occurs. | |
2797 | ||
3d13052d | 2798 | .. index:: neighbor A.B.C.D advertise-map NAME [exist-map|non-exist-map] NAME |
7f7940e6 MK |
2799 | .. clicmd:: [no] neighbor A.B.C.D advertise-map NAME [exist-map|non-exist-map] NAME |
2800 | ||
fa36596c | 2801 | This command enables BGP scanner process to monitor routes specified by |
7f7940e6 | 2802 | exist-map or non-exist-map command in BGP table and conditionally advertises |
fa36596c | 2803 | the routes specified by advertise-map command. |
7f7940e6 MK |
2804 | |
2805 | Sample Configuration | |
2806 | ^^^^^^^^^^^^^^^^^^^^^ | |
2807 | .. code-block:: frr | |
2808 | ||
fa36596c MK |
2809 | interface enp0s9 |
2810 | ip address 10.10.10.2/24 | |
2811 | ! | |
2812 | interface enp0s10 | |
2813 | ip address 10.10.20.2/24 | |
2814 | ! | |
7f7940e6 | 2815 | interface lo |
fa36596c | 2816 | ip address 203.0.113.1/32 |
7f7940e6 MK |
2817 | ! |
2818 | router bgp 2 | |
2819 | bgp log-neighbor-changes | |
2820 | no bgp ebgp-requires-policy | |
2821 | neighbor 10.10.10.1 remote-as 1 | |
2822 | neighbor 10.10.20.3 remote-as 3 | |
2823 | ! | |
2824 | address-family ipv4 unicast | |
7f7940e6 | 2825 | neighbor 10.10.10.1 soft-reconfiguration inbound |
7f7940e6 | 2826 | neighbor 10.10.20.3 soft-reconfiguration inbound |
fa36596c | 2827 | neighbor 10.10.20.3 advertise-map ADV-MAP non-exist-map EXIST-MAP |
7f7940e6 MK |
2828 | exit-address-family |
2829 | ! | |
fa36596c MK |
2830 | ip prefix-list DEFAULT seq 5 permit 192.0.2.5/32 |
2831 | ip prefix-list DEFAULT seq 10 permit 192.0.2.1/32 | |
2832 | ip prefix-list EXIST seq 5 permit 10.10.10.10/32 | |
2833 | ip prefix-list DEFAULT-ROUTE seq 5 permit 0.0.0.0/0 | |
2834 | ip prefix-list IP1 seq 5 permit 10.139.224.0/20 | |
2835 | ! | |
2836 | bgp community-list standard DC-ROUTES seq 5 permit 64952:3008 | |
2837 | bgp community-list standard DC-ROUTES seq 10 permit 64671:501 | |
2838 | bgp community-list standard DC-ROUTES seq 15 permit 64950:3009 | |
2839 | bgp community-list standard DEFAULT-ROUTE seq 5 permit 65013:200 | |
7f7940e6 | 2840 | ! |
fa36596c MK |
2841 | route-map ADV-MAP permit 10 |
2842 | match ip address prefix-list IP1 | |
7f7940e6 | 2843 | ! |
fa36596c MK |
2844 | route-map ADV-MAP permit 20 |
2845 | match community DC-ROUTES | |
2846 | ! | |
2847 | route-map EXIST-MAP permit 10 | |
2848 | match community DEFAULT-ROUTE | |
2849 | match ip address prefix-list DEFAULT-ROUTE | |
7f7940e6 MK |
2850 | ! |
2851 | ||
2852 | Sample Output | |
2853 | ^^^^^^^^^^^^^ | |
2854 | ||
fa36596c | 2855 | When default route is present in R2'2 BGP table, 10.139.224.0/20 and 192.0.2.1/32 are not advertised to R3. |
7f7940e6 MK |
2856 | |
2857 | .. code-block:: frr | |
2858 | ||
2859 | Router2# show ip bgp | |
fa36596c | 2860 | BGP table version is 20, local router ID is 203.0.113.1, vrf id 0 |
7f7940e6 MK |
2861 | Default local pref 100, local AS 2 |
2862 | Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, | |
2863 | i internal, r RIB-failure, S Stale, R Removed | |
2864 | Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self | |
2865 | Origin codes: i - IGP, e - EGP, ? - incomplete | |
2866 | ||
fa36596c MK |
2867 | Network Next Hop Metric LocPrf Weight Path |
2868 | *> 0.0.0.0/0 10.10.10.1 0 0 1 i | |
2869 | *> 10.139.224.0/20 10.10.10.1 0 0 1 ? | |
2870 | *> 192.0.2.1/32 10.10.10.1 0 0 1 i | |
2871 | *> 192.0.2.5/32 10.10.10.1 0 0 1 i | |
7f7940e6 MK |
2872 | |
2873 | Displayed 4 routes and 4 total paths | |
fa36596c | 2874 | Router2# show ip bgp neighbors 10.10.20.3 |
7f7940e6 MK |
2875 | |
2876 | !--- Output suppressed. | |
2877 | ||
2878 | For address family: IPv4 Unicast | |
fa36596c | 2879 | Update group 7, subgroup 7 |
7f7940e6 MK |
2880 | Packet Queue length 0 |
2881 | Inbound soft reconfiguration allowed | |
2882 | Community attribute sent to this neighbor(all) | |
fa36596c MK |
2883 | Condition NON_EXIST, Condition-map *EXIST-MAP, Advertise-map *ADV-MAP, status: Withdraw |
2884 | 0 accepted prefixes | |
7f7940e6 MK |
2885 | |
2886 | !--- Output suppressed. | |
2887 | ||
fa36596c MK |
2888 | Router2# show ip bgp neighbors 10.10.20.3 advertised-routes |
2889 | BGP table version is 20, local router ID is 203.0.113.1, vrf id 0 | |
7f7940e6 MK |
2890 | Default local pref 100, local AS 2 |
2891 | Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, | |
fa36596c | 2892 | i internal, r RIB-failure, S Stale, R Removed |
7f7940e6 MK |
2893 | Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self |
2894 | Origin codes: i - IGP, e - EGP, ? - incomplete | |
2895 | ||
fa36596c MK |
2896 | Network Next Hop Metric LocPrf Weight Path |
2897 | *> 0.0.0.0/0 0.0.0.0 0 1 i | |
2898 | *> 192.0.2.5/32 0.0.0.0 0 1 i | |
7f7940e6 | 2899 | |
fa36596c | 2900 | Total number of prefixes 2 |
7f7940e6 | 2901 | |
fa36596c | 2902 | When default route is not present in R2'2 BGP table, 10.139.224.0/20 and 192.0.2.1/32 are advertised to R3. |
7f7940e6 MK |
2903 | |
2904 | .. code-block:: frr | |
2905 | ||
2906 | Router2# show ip bgp | |
fa36596c | 2907 | BGP table version is 21, local router ID is 203.0.113.1, vrf id 0 |
7f7940e6 MK |
2908 | Default local pref 100, local AS 2 |
2909 | Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, | |
2910 | i internal, r RIB-failure, S Stale, R Removed | |
2911 | Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self | |
2912 | Origin codes: i - IGP, e - EGP, ? - incomplete | |
2913 | ||
fa36596c MK |
2914 | Network Next Hop Metric LocPrf Weight Path |
2915 | *> 10.139.224.0/20 10.10.10.1 0 0 1 ? | |
2916 | *> 192.0.2.1/32 10.10.10.1 0 0 1 i | |
2917 | *> 192.0.2.5/32 10.10.10.1 0 0 1 i | |
7f7940e6 MK |
2918 | |
2919 | Displayed 3 routes and 3 total paths | |
7f7940e6 | 2920 | |
fa36596c | 2921 | Router2# show ip bgp neighbors 10.10.20.3 |
7f7940e6 MK |
2922 | |
2923 | !--- Output suppressed. | |
2924 | ||
2925 | For address family: IPv4 Unicast | |
fa36596c | 2926 | Update group 7, subgroup 7 |
7f7940e6 MK |
2927 | Packet Queue length 0 |
2928 | Inbound soft reconfiguration allowed | |
2929 | Community attribute sent to this neighbor(all) | |
fa36596c MK |
2930 | Condition NON_EXIST, Condition-map *EXIST-MAP, Advertise-map *ADV-MAP, status: Advertise |
2931 | 0 accepted prefixes | |
7f7940e6 MK |
2932 | |
2933 | !--- Output suppressed. | |
2934 | ||
fa36596c MK |
2935 | Router2# show ip bgp neighbors 10.10.20.3 advertised-routes |
2936 | BGP table version is 21, local router ID is 203.0.113.1, vrf id 0 | |
7f7940e6 MK |
2937 | Default local pref 100, local AS 2 |
2938 | Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, | |
2939 | i internal, r RIB-failure, S Stale, R Removed | |
2940 | Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self | |
2941 | Origin codes: i - IGP, e - EGP, ? - incomplete | |
2942 | ||
fa36596c MK |
2943 | Network Next Hop Metric LocPrf Weight Path |
2944 | *> 10.139.224.0/20 0.0.0.0 0 1 ? | |
2945 | *> 192.0.2.1/32 0.0.0.0 0 1 i | |
2946 | *> 192.0.2.5/32 0.0.0.0 0 1 i | |
7f7940e6 MK |
2947 | |
2948 | Total number of prefixes 3 | |
fa36596c | 2949 | Router2# |
7f7940e6 | 2950 | |
8fcedbd2 QY |
2951 | .. _bgp-debugging: |
2952 | ||
2953 | Debugging | |
2954 | --------- | |
42fc5d26 | 2955 | |
c1a54c05 | 2956 | .. index:: show debug |
29adcd50 | 2957 | .. clicmd:: show debug |
42fc5d26 | 2958 | |
8fcedbd2 | 2959 | Show all enabled debugs. |
42fc5d26 | 2960 | |
54422b46 DS |
2961 | .. index:: show bgp listeners |
2962 | .. clicmd:: show bgp listeners | |
2963 | ||
2964 | Display Listen sockets and the vrf that created them. Useful for debugging of when | |
2965 | listen is not working and this is considered a developer debug statement. | |
2966 | ||
3d13052d | 2967 | .. index:: debug bgp neighbor-events |
53b758f3 | 2968 | .. clicmd:: [no] debug bgp neighbor-events |
42fc5d26 | 2969 | |
8fcedbd2 QY |
2970 | Enable or disable debugging for neighbor events. This provides general |
2971 | information on BGP events such as peer connection / disconnection, session | |
2972 | establishment / teardown, and capability negotiation. | |
42fc5d26 | 2973 | |
3d13052d | 2974 | .. index:: debug bgp updates |
53b758f3 | 2975 | .. clicmd:: [no] debug bgp updates |
42fc5d26 | 2976 | |
8fcedbd2 QY |
2977 | Enable or disable debugging for BGP updates. This provides information on |
2978 | BGP UPDATE messages transmitted and received between local and remote | |
2979 | instances. | |
42fc5d26 | 2980 | |
3d13052d | 2981 | .. index:: debug bgp keepalives |
53b758f3 | 2982 | .. clicmd:: [no] debug bgp keepalives |
42fc5d26 | 2983 | |
8fcedbd2 QY |
2984 | Enable or disable debugging for BGP keepalives. This provides information on |
2985 | BGP KEEPALIVE messages transmitted and received between local and remote | |
2986 | instances. | |
c1a54c05 | 2987 | |
3d13052d | 2988 | .. index:: debug bgp bestpath <A.B.C.D/M|X:X::X:X/M> |
8fcedbd2 | 2989 | .. clicmd:: [no] debug bgp bestpath <A.B.C.D/M|X:X::X:X/M> |
42fc5d26 | 2990 | |
8fcedbd2 | 2991 | Enable or disable debugging for bestpath selection on the specified prefix. |
42fc5d26 | 2992 | |
3d13052d | 2993 | .. index:: debug bgp nht |
8fcedbd2 | 2994 | .. clicmd:: [no] debug bgp nht |
4da7fda3 | 2995 | |
8fcedbd2 | 2996 | Enable or disable debugging of BGP nexthop tracking. |
4da7fda3 | 2997 | |
3d13052d | 2998 | .. index:: debug bgp update-groups |
8fcedbd2 | 2999 | .. clicmd:: [no] debug bgp update-groups |
4b44467c | 3000 | |
8fcedbd2 QY |
3001 | Enable or disable debugging of dynamic update groups. This provides general |
3002 | information on group creation, deletion, join and prune events. | |
4b44467c | 3003 | |
3d13052d | 3004 | .. index:: debug bgp zebra |
8fcedbd2 | 3005 | .. clicmd:: [no] debug bgp zebra |
42fc5d26 | 3006 | |
8fcedbd2 | 3007 | Enable or disable debugging of communications between *bgpd* and *zebra*. |
c3c5a71f | 3008 | |
8fcedbd2 QY |
3009 | Dumping Messages and Routing Tables |
3010 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
42fc5d26 | 3011 | |
8fcedbd2 QY |
3012 | .. index:: dump bgp all PATH [INTERVAL] |
3013 | .. clicmd:: dump bgp all PATH [INTERVAL] | |
42fc5d26 | 3014 | |
8fcedbd2 QY |
3015 | .. index:: dump bgp all-et PATH [INTERVAL] |
3016 | .. clicmd:: dump bgp all-et PATH [INTERVAL] | |
c3c5a71f | 3017 | |
3d13052d | 3018 | .. index:: dump bgp all [PATH] [INTERVAL] |
8fcedbd2 | 3019 | .. clicmd:: no dump bgp all [PATH] [INTERVAL] |
42fc5d26 | 3020 | |
8fcedbd2 QY |
3021 | Dump all BGP packet and events to `path` file. |
3022 | If `interval` is set, a new file will be created for echo `interval` of | |
3023 | seconds. The path `path` can be set with date and time formatting | |
3024 | (strftime). The type ‘all-et’ enables support for Extended Timestamp Header | |
3025 | (:ref:`packet-binary-dump-format`). | |
c3c5a71f | 3026 | |
8fcedbd2 QY |
3027 | .. index:: dump bgp updates PATH [INTERVAL] |
3028 | .. clicmd:: dump bgp updates PATH [INTERVAL] | |
42fc5d26 | 3029 | |
8fcedbd2 QY |
3030 | .. index:: dump bgp updates-et PATH [INTERVAL] |
3031 | .. clicmd:: dump bgp updates-et PATH [INTERVAL] | |
42fc5d26 | 3032 | |
3d13052d | 3033 | .. index:: dump bgp updates [PATH] [INTERVAL] |
8fcedbd2 | 3034 | .. clicmd:: no dump bgp updates [PATH] [INTERVAL] |
42fc5d26 | 3035 | |
8fcedbd2 QY |
3036 | Dump only BGP updates messages to `path` file. |
3037 | If `interval` is set, a new file will be created for echo `interval` of | |
3038 | seconds. The path `path` can be set with date and time formatting | |
3039 | (strftime). The type ‘updates-et’ enables support for Extended Timestamp | |
3040 | Header (:ref:`packet-binary-dump-format`). | |
42fc5d26 | 3041 | |
8fcedbd2 QY |
3042 | .. index:: dump bgp routes-mrt PATH |
3043 | .. clicmd:: dump bgp routes-mrt PATH | |
c3c5a71f | 3044 | |
8fcedbd2 QY |
3045 | .. index:: dump bgp routes-mrt PATH INTERVAL |
3046 | .. clicmd:: dump bgp routes-mrt PATH INTERVAL | |
42fc5d26 | 3047 | |
3d13052d | 3048 | .. index:: dump bgp route-mrt [PATH] [INTERVAL] |
8fcedbd2 | 3049 | .. clicmd:: no dump bgp route-mrt [PATH] [INTERVAL] |
42fc5d26 | 3050 | |
8fcedbd2 QY |
3051 | Dump whole BGP routing table to `path`. This is heavy process. The path |
3052 | `path` can be set with date and time formatting (strftime). If `interval` is | |
3053 | set, a new file will be created for echo `interval` of seconds. | |
42fc5d26 | 3054 | |
8fcedbd2 | 3055 | Note: the interval variable can also be set using hours and minutes: 04h20m00. |
42fc5d26 | 3056 | |
c3c5a71f | 3057 | |
8fcedbd2 | 3058 | .. _bgp-other-commands: |
42fc5d26 | 3059 | |
8fcedbd2 QY |
3060 | Other BGP Commands |
3061 | ------------------ | |
42fc5d26 | 3062 | |
e312b6c6 QY |
3063 | The following are available in the top level *enable* mode: |
3064 | ||
dc912615 DS |
3065 | .. index:: clear bgp \* |
3066 | .. clicmd:: clear bgp \* | |
3067 | ||
3068 | Clear all peers. | |
3069 | ||
8fcedbd2 QY |
3070 | .. index:: clear bgp ipv4|ipv6 \* |
3071 | .. clicmd:: clear bgp ipv4|ipv6 \* | |
42fc5d26 | 3072 | |
dc912615 DS |
3073 | Clear all peers with this address-family activated. |
3074 | ||
3075 | .. index:: clear bgp ipv4|ipv6 unicast \* | |
3076 | .. clicmd:: clear bgp ipv4|ipv6 unicast \* | |
3077 | ||
3078 | Clear all peers with this address-family and sub-address-family activated. | |
42fc5d26 | 3079 | |
8fcedbd2 QY |
3080 | .. index:: clear bgp ipv4|ipv6 PEER |
3081 | .. clicmd:: clear bgp ipv4|ipv6 PEER | |
42fc5d26 | 3082 | |
dc912615 DS |
3083 | Clear peers with address of X.X.X.X and this address-family activated. |
3084 | ||
3085 | .. index:: clear bgp ipv4|ipv6 unicast PEER | |
3086 | .. clicmd:: clear bgp ipv4|ipv6 unicast PEER | |
3087 | ||
3088 | Clear peer with address of X.X.X.X and this address-family and sub-address-family activated. | |
3089 | ||
3090 | .. index:: clear bgp ipv4|ipv6 PEER soft|in|out | |
3091 | .. clicmd:: clear bgp ipv4|ipv6 PEER soft|in|out | |
3092 | ||
3093 | Clear peer using soft reconfiguration in this address-family. | |
42fc5d26 | 3094 | |
dc912615 DS |
3095 | .. index:: clear bgp ipv4|ipv6 unicast PEER soft|in|out |
3096 | .. clicmd:: clear bgp ipv4|ipv6 unicast PEER soft|in|out | |
42fc5d26 | 3097 | |
dc912615 | 3098 | Clear peer using soft reconfiguration in this address-family and sub-address-family. |
42fc5d26 | 3099 | |
e312b6c6 QY |
3100 | The following are available in the ``router bgp`` mode: |
3101 | ||
3102 | .. index:: write-quanta (1-64) | |
3103 | .. clicmd:: write-quanta (1-64) | |
3104 | ||
3105 | BGP message Tx I/O is vectored. This means that multiple packets are written | |
3106 | to the peer socket at the same time each I/O cycle, in order to minimize | |
3107 | system call overhead. This value controls how many are written at a time. | |
3108 | Under certain load conditions, reducing this value could make peer traffic | |
3109 | less 'bursty'. In practice, leave this settings on the default (64) unless | |
3110 | you truly know what you are doing. | |
3111 | ||
3112 | .. index:: read-quanta (1-10) | |
dad83b67 | 3113 | .. clicmd:: read-quanta (1-10) |
e312b6c6 QY |
3114 | |
3115 | Unlike Tx, BGP Rx traffic is not vectored. Packets are read off the wire one | |
3116 | at a time in a loop. This setting controls how many iterations the loop runs | |
3117 | for. As with write-quanta, it is best to leave this setting on the default. | |
42fc5d26 | 3118 | |
05bd726c | 3119 | The following command is available in ``config`` mode as well as in the |
3120 | ``router bgp`` mode: | |
3121 | ||
3122 | .. index:: bgp graceful-shutdown | |
3123 | .. clicmd:: bgp graceful-shutdown | |
3124 | ||
3125 | The purpose of this command is to initiate BGP Graceful Shutdown which | |
3126 | is described in :rfc:`8326`. The use case for this is to minimize or | |
3127 | eliminate the amount of traffic loss in a network when a planned | |
3128 | maintenance activity such as software upgrade or hardware replacement | |
3129 | is to be performed on a router. The feature works by re-announcing | |
3130 | routes to eBGP peers with the GRACEFUL_SHUTDOWN community included. | |
3131 | Peers are then expected to treat such paths with the lowest preference. | |
3132 | This happens automatically on a receiver running FRR; with other | |
3133 | routing protocol stacks, an inbound policy may have to be configured. | |
3134 | In FRR, triggering graceful shutdown also results in announcing a | |
3135 | LOCAL_PREF of 0 to iBGP peers. | |
3136 | ||
3137 | Graceful shutdown can be configured per BGP instance or globally for | |
3138 | all of BGP. These two options are mutually exclusive. The no form of | |
3139 | the command causes graceful shutdown to be stopped, and routes will | |
3140 | be re-announced without the GRACEFUL_SHUTDOWN community and/or with | |
3141 | the usual LOCAL_PREF value. Note that if this option is saved to | |
3142 | the startup configuration, graceful shutdown will remain in effect | |
3143 | across restarts of *bgpd* and will need to be explicitly disabled. | |
3144 | ||
8fcedbd2 | 3145 | .. _bgp-displaying-bgp-information: |
42fc5d26 | 3146 | |
8fcedbd2 QY |
3147 | Displaying BGP Information |
3148 | ========================== | |
42fc5d26 | 3149 | |
e6f59415 PG |
3150 | The following four commands display the IPv6 and IPv4 routing tables, depending |
3151 | on whether or not the ``ip`` keyword is used. | |
3152 | Actually, :clicmd:`show ip bgp` command was used on older `Quagga` routing | |
3153 | daemon project, while :clicmd:`show bgp` command is the new format. The choice | |
3154 | has been done to keep old format with IPv4 routing table, while new format | |
3155 | displays IPv6 routing table. | |
3156 | ||
96f3485c MK |
3157 | .. index:: show ip bgp [all] [wide|json] |
3158 | .. clicmd:: show ip bgp [all] [wide|json] | |
42fc5d26 | 3159 | |
96f3485c MK |
3160 | .. index:: show ip bgp A.B.C.D [json] |
3161 | .. clicmd:: show ip bgp A.B.C.D [json] | |
c1a54c05 | 3162 | |
96f3485c MK |
3163 | .. index:: show bgp [all] [wide|json] |
3164 | .. clicmd:: show bgp [all] [wide|json] | |
e6f59415 | 3165 | |
96f3485c MK |
3166 | .. index:: show bgp X:X::X:X [json] |
3167 | .. clicmd:: show bgp X:X::X:X [json] | |
42fc5d26 | 3168 | |
8fcedbd2 | 3169 | These commands display BGP routes. When no route is specified, the default |
e6f59415 | 3170 | is to display all BGP routes. |
42fc5d26 | 3171 | |
8fcedbd2 | 3172 | :: |
c1a54c05 | 3173 | |
8fcedbd2 QY |
3174 | BGP table version is 0, local router ID is 10.1.1.1 |
3175 | Status codes: s suppressed, d damped, h history, * valid, > best, i - internal | |
3176 | Origin codes: i - IGP, e - EGP, ? - incomplete | |
42fc5d26 | 3177 | |
8fcedbd2 QY |
3178 | Network Next Hop Metric LocPrf Weight Path |
3179 | \*> 1.1.1.1/32 0.0.0.0 0 32768 i | |
42fc5d26 | 3180 | |
8fcedbd2 | 3181 | Total number of prefixes 1 |
4da7fda3 | 3182 | |
56c07345 | 3183 | If ``wide`` option is specified, then the prefix table's width is increased |
986b0fc3 DA |
3184 | to fully display the prefix and the nexthop. |
3185 | ||
3186 | This is especially handy dealing with IPv6 prefixes and | |
3187 | if :clicmd:`[no] bgp default show-nexthop-hostname` is enabled. | |
3188 | ||
56c07345 | 3189 | If ``all`` option is specified, ``ip`` keyword is ignored, show bgp all and |
96f3485c MK |
3190 | show ip bgp all commands display routes for all AFIs and SAFIs. |
3191 | ||
56c07345 | 3192 | If ``json`` option is specified, output is displayed in JSON format. |
96f3485c | 3193 | |
e6f59415 PG |
3194 | Some other commands provide additional options for filtering the output. |
3195 | ||
3196 | .. index:: show [ip] bgp regexp LINE | |
3197 | .. clicmd:: show [ip] bgp regexp LINE | |
42fc5d26 | 3198 | |
8fcedbd2 QY |
3199 | This command displays BGP routes using AS path regular expression |
3200 | (:ref:`bgp-regular-expressions`). | |
42fc5d26 | 3201 | |
96f3485c MK |
3202 | .. index:: show [ip] bgp [all] summary [json] |
3203 | .. clicmd:: show [ip] bgp [all] summary [json] | |
42fc5d26 | 3204 | |
8fcedbd2 | 3205 | Show a bgp peer summary for the specified address family. |
42fc5d26 | 3206 | |
e6f59415 PG |
3207 | The old command structure :clicmd:`show ip bgp` may be removed in the future |
3208 | and should no longer be used. In order to reach the other BGP routing tables | |
3209 | other than the IPv6 routing table given by :clicmd:`show bgp`, the new command | |
3210 | structure is extended with :clicmd:`show bgp [afi] [safi]`. | |
3211 | ||
96f3485c MK |
3212 | .. index:: show bgp [afi] [safi] [all] [wide|json] |
3213 | .. clicmd:: show bgp [afi] [safi] [all] [wide|json] | |
e6f59415 PG |
3214 | |
3215 | .. index:: show bgp <ipv4|ipv6> <unicast|multicast|vpn|labeled-unicast> | |
3216 | .. clicmd:: show bgp <ipv4|ipv6> <unicast|multicast|vpn|labeled-unicast> | |
3217 | ||
3218 | These commands display BGP routes for the specific routing table indicated by | |
3219 | the selected afi and the selected safi. If no afi and no safi value is given, | |
6cfd16ad TA |
3220 | the command falls back to the default IPv6 routing table. |
3221 | For EVPN prefixes, you can display the full BGP table for this AFI/SAFI | |
3222 | using the standard `show bgp [afi] [safi]` syntax. | |
3223 | ||
3224 | .. index:: show bgp l2vpn evpn route [type <macip|2|multicast|3|es|4|prefix|5>] | |
3225 | .. clicmd:: show bgp l2vpn evpn route [type <macip|2|multicast|3|es|4|prefix|5>] | |
3226 | ||
3227 | Additionally, you can also filter this output by route type. | |
e6f59415 | 3228 | |
96f3485c MK |
3229 | .. index:: show bgp [afi] [safi] [all] summary [json] |
3230 | .. clicmd:: show bgp [afi] [safi] [all] summary [json] | |
e6f59415 PG |
3231 | |
3232 | Show a bgp peer summary for the specified address family, and subsequent | |
3233 | address-family. | |
3234 | ||
96f3485c MK |
3235 | .. index:: show bgp [afi] [safi] [all] summary failed [json] |
3236 | .. clicmd:: show bgp [afi] [safi] [all] summary failed [json] | |
3577f1c5 DD |
3237 | |
3238 | Show a bgp peer summary for peers that are not succesfully exchanging routes | |
3239 | for the specified address family, and subsequent address-family. | |
3240 | ||
96f3485c MK |
3241 | .. index:: show bgp [afi] [safi] [all] summary established [json] |
3242 | .. clicmd:: show bgp [afi] [safi] [all] summary established [json] | |
1c027267 DA |
3243 | |
3244 | Show a bgp peer summary for peers that are succesfully exchanging routes | |
3245 | for the specified address family, and subsequent address-family. | |
3246 | ||
e6f59415 PG |
3247 | .. index:: show bgp [afi] [safi] neighbor [PEER] |
3248 | .. clicmd:: show bgp [afi] [safi] neighbor [PEER] | |
9eb95b3b | 3249 | |
e6f59415 PG |
3250 | This command shows information on a specific BGP peer of the relevant |
3251 | afi and safi selected. | |
c1a54c05 | 3252 | |
96f3485c MK |
3253 | .. index:: show bgp [afi] [safi] [all] dampening dampened-paths [wide|json] |
3254 | .. clicmd:: show bgp [afi] [safi] [all] dampening dampened-paths [wide|json] | |
42fc5d26 | 3255 | |
e6f59415 PG |
3256 | Display paths suppressed due to dampening of the selected afi and safi |
3257 | selected. | |
42fc5d26 | 3258 | |
96f3485c MK |
3259 | .. index:: show bgp [afi] [safi] [all] dampening flap-statistics [wide|json] |
3260 | .. clicmd:: show bgp [afi] [safi] [all] dampening flap-statistics [wide|json] | |
c1a54c05 | 3261 | |
e6f59415 | 3262 | Display flap statistics of routes of the selected afi and safi selected. |
42fc5d26 | 3263 | |
620e23e8 PG |
3264 | .. index:: show bgp [afi] [safi] statistics |
3265 | .. clicmd:: show bgp [afi] [safi] statistics | |
3266 | ||
3267 | Display statistics of routes of the selected afi and safi. | |
3268 | ||
3269 | .. index:: show bgp statistics-all | |
3270 | .. clicmd:: show bgp statistics-all | |
3271 | ||
3272 | Display statistics of routes of all the afi and safi. | |
3273 | ||
96f3485c MK |
3274 | .. index:: show [ip] bgp [afi] [safi] [all] cidr-only [wide|json] |
3275 | .. clicmd:: show [ip] bgp [afi] [safi] [all] cidr-only [wide|json] | |
3276 | ||
3277 | Display routes with non-natural netmasks. | |
3278 | ||
3279 | .. index:: show [ip] bgp [afi] [safi] [all] neighbors A.B.C.D [advertised-routes|received-routes|filtered-routes] [json|wide] | |
3280 | .. clicmd:: show [ip] bgp [afi] [safi] [all] neighbors A.B.C.D [advertised-routes|received-routes|filtered-routes] [json|wide] | |
3281 | ||
3282 | Display the routes advertised to a BGP neighbor or received routes | |
3283 | from neighbor or filtered routes received from neighbor based on the | |
3284 | option specified. | |
3285 | ||
56c07345 | 3286 | If ``wide`` option is specified, then the prefix table's width is increased |
96f3485c MK |
3287 | to fully display the prefix and the nexthop. |
3288 | ||
3289 | This is especially handy dealing with IPv6 prefixes and | |
3290 | if :clicmd:`[no] bgp default show-nexthop-hostname` is enabled. | |
3291 | ||
56c07345 | 3292 | If ``all`` option is specified, ``ip`` keyword is ignored and, |
96f3485c | 3293 | routes displayed for all AFIs and SAFIs. |
56c07345 | 3294 | if afi is specified, with ``all`` option, routes will be displayed for |
96f3485c MK |
3295 | each SAFI in the selcted AFI |
3296 | ||
56c07345 | 3297 | If ``json`` option is specified, output is displayed in JSON format. |
96f3485c | 3298 | |
8fcedbd2 | 3299 | .. _bgp-display-routes-by-community: |
42fc5d26 | 3300 | |
8fcedbd2 QY |
3301 | Displaying Routes by Community Attribute |
3302 | ---------------------------------------- | |
42fc5d26 | 3303 | |
8fcedbd2 QY |
3304 | The following commands allow displaying routes based on their community |
3305 | attribute. | |
42fc5d26 | 3306 | |
96f3485c MK |
3307 | .. index:: show [ip] bgp <ipv4|ipv6> [all] community [wide|json] |
3308 | .. clicmd:: show [ip] bgp <ipv4|ipv6> [all] community [wide|json] | |
42fc5d26 | 3309 | |
96f3485c MK |
3310 | .. index:: show [ip] bgp <ipv4|ipv6> [all] community COMMUNITY [wide|json] |
3311 | .. clicmd:: show [ip] bgp <ipv4|ipv6> [all] community COMMUNITY [wide|json] | |
42fc5d26 | 3312 | |
96f3485c MK |
3313 | .. index:: show [ip] bgp <ipv4|ipv6> [all] community COMMUNITY exact-match [wide|json] |
3314 | .. clicmd:: show [ip] bgp <ipv4|ipv6> [all] community COMMUNITY exact-match [wide|json] | |
76bd1499 | 3315 | |
8fcedbd2 QY |
3316 | These commands display BGP routes which have the community attribute. |
3317 | attribute. When ``COMMUNITY`` is specified, BGP routes that match that | |
3318 | community are displayed. When `exact-match` is specified, it display only | |
3319 | routes that have an exact match. | |
c3c5a71f | 3320 | |
8fcedbd2 QY |
3321 | .. index:: show [ip] bgp <ipv4|ipv6> community-list WORD |
3322 | .. clicmd:: show [ip] bgp <ipv4|ipv6> community-list WORD | |
42fc5d26 | 3323 | |
8fcedbd2 QY |
3324 | .. index:: show [ip] bgp <ipv4|ipv6> community-list WORD exact-match |
3325 | .. clicmd:: show [ip] bgp <ipv4|ipv6> community-list WORD exact-match | |
42fc5d26 | 3326 | |
8fcedbd2 QY |
3327 | These commands display BGP routes for the address family specified that |
3328 | match the specified community list. When `exact-match` is specified, it | |
3329 | displays only routes that have an exact match. | |
42fc5d26 | 3330 | |
56c07345 | 3331 | If ``wide`` option is specified, then the prefix table's width is increased |
96f3485c MK |
3332 | to fully display the prefix and the nexthop. |
3333 | ||
3334 | This is especially handy dealing with IPv6 prefixes and | |
3335 | if :clicmd:`[no] bgp default show-nexthop-hostname` is enabled. | |
3336 | ||
56c07345 | 3337 | If ``all`` option is specified, ``ip`` keyword is ignored and, |
96f3485c | 3338 | routes displayed for all AFIs and SAFIs. |
56c07345 | 3339 | if afi is specified, with ``all`` option, routes will be displayed for |
96f3485c MK |
3340 | each SAFI in the selcted AFI |
3341 | ||
56c07345 | 3342 | If ``json`` option is specified, output is displayed in JSON format. |
96f3485c | 3343 | |
36a206db | 3344 | .. _bgp-display-routes-by-lcommunity: |
3345 | ||
3346 | Displaying Routes by Large Community Attribute | |
3347 | ---------------------------------------------- | |
3348 | ||
ac2201bb | 3349 | The following commands allow displaying routes based on their |
36a206db | 3350 | large community attribute. |
3351 | ||
3352 | .. index:: show [ip] bgp <ipv4|ipv6> large-community | |
3353 | .. clicmd:: show [ip] bgp <ipv4|ipv6> large-community | |
3354 | ||
3355 | .. index:: show [ip] bgp <ipv4|ipv6> large-community LARGE-COMMUNITY | |
3356 | .. clicmd:: show [ip] bgp <ipv4|ipv6> large-community LARGE-COMMUNITY | |
3357 | ||
3358 | .. index:: show [ip] bgp <ipv4|ipv6> large-community LARGE-COMMUNITY exact-match | |
3359 | .. clicmd:: show [ip] bgp <ipv4|ipv6> large-community LARGE-COMMUNITY exact-match | |
3360 | ||
3361 | .. index:: show [ip] bgp <ipv4|ipv6> large-community LARGE-COMMUNITY json | |
3362 | .. clicmd:: show [ip] bgp <ipv4|ipv6> large-community LARGE-COMMUNITY json | |
3363 | ||
3364 | These commands display BGP routes which have the large community attribute. | |
3365 | attribute. When ``LARGE-COMMUNITY`` is specified, BGP routes that match that | |
ac2201bb DA |
3366 | large community are displayed. When `exact-match` is specified, it display |
3367 | only routes that have an exact match. When `json` is specified, it display | |
36a206db | 3368 | routes in json format. |
3369 | ||
3370 | .. index:: show [ip] bgp <ipv4|ipv6> large-community-list WORD | |
3371 | .. clicmd:: show [ip] bgp <ipv4|ipv6> large-community-list WORD | |
3372 | ||
3373 | .. index:: show [ip] bgp <ipv4|ipv6> large-community-list WORD exact-match | |
3374 | .. clicmd:: show [ip] bgp <ipv4|ipv6> large-community-list WORD exact-match | |
3375 | ||
3376 | .. index:: show [ip] bgp <ipv4|ipv6> large-community-list WORD json | |
3377 | .. clicmd:: show [ip] bgp <ipv4|ipv6> large-community-list WORD json | |
3378 | ||
3379 | These commands display BGP routes for the address family specified that | |
ac2201bb DA |
3380 | match the specified large community list. When `exact-match` is specified, |
3381 | it displays only routes that have an exact match. When `json` is specified, | |
36a206db | 3382 | it display routes in json format. |
3383 | ||
8fcedbd2 | 3384 | .. _bgp-display-routes-by-as-path: |
42fc5d26 | 3385 | |
36a206db | 3386 | |
8fcedbd2 QY |
3387 | Displaying Routes by AS Path |
3388 | ---------------------------- | |
42fc5d26 | 3389 | |
8fcedbd2 QY |
3390 | .. index:: show bgp ipv4|ipv6 regexp LINE |
3391 | .. clicmd:: show bgp ipv4|ipv6 regexp LINE | |
76bd1499 | 3392 | |
8fcedbd2 QY |
3393 | This commands displays BGP routes that matches a regular |
3394 | expression `line` (:ref:`bgp-regular-expressions`). | |
3395 | ||
e6f59415 PG |
3396 | .. index:: show [ip] bgp ipv4 vpn |
3397 | .. clicmd:: show [ip] bgp ipv4 vpn | |
8fcedbd2 | 3398 | |
e6f59415 PG |
3399 | .. index:: show [ip] bgp ipv6 vpn |
3400 | .. clicmd:: show [ip] bgp ipv6 vpn | |
8fcedbd2 QY |
3401 | |
3402 | Print active IPV4 or IPV6 routes advertised via the VPN SAFI. | |
3403 | ||
3404 | .. index:: show bgp ipv4 vpn summary | |
3405 | .. clicmd:: show bgp ipv4 vpn summary | |
3406 | ||
3407 | .. index:: show bgp ipv6 vpn summary | |
3408 | .. clicmd:: show bgp ipv6 vpn summary | |
3409 | ||
3410 | Print a summary of neighbor connections for the specified AFI/SAFI combination. | |
3411 | ||
09d78f10 DS |
3412 | Displaying Update Group Information |
3413 | ----------------------------------- | |
3414 | ||
6c5be52a SR |
3415 | .. index:: show bgp update-groups SUBGROUP-ID [advertise-queue|advertised-routes|packet-queue] |
3416 | .. clicmd:: show bgp update-groups [advertise-queue|advertised-routes|packet-queue] | |
09d78f10 DS |
3417 | |
3418 | Display Information about each individual update-group being used. | |
3419 | If SUBGROUP-ID is specified only display about that particular group. If | |
3420 | advertise-queue is specified the list of routes that need to be sent | |
3421 | to the peers in the update-group is displayed, advertised-routes means | |
a64e0ee5 | 3422 | the list of routes we have sent to the peers in the update-group and |
09d78f10 DS |
3423 | packet-queue specifies the list of packets in the queue to be sent. |
3424 | ||
6c5be52a SR |
3425 | .. index:: show bgp update-groups statistics |
3426 | .. clicmd:: show bgp update-groups statistics | |
09d78f10 DS |
3427 | |
3428 | Display Information about update-group events in FRR. | |
8fcedbd2 QY |
3429 | |
3430 | .. _bgp-route-reflector: | |
3431 | ||
3432 | Route Reflector | |
3433 | =============== | |
3434 | ||
749afd7d RF |
3435 | BGP routers connected inside the same AS through BGP belong to an internal |
3436 | BGP session, or IBGP. In order to prevent routing table loops, IBGP does not | |
3437 | advertise IBGP-learned routes to other routers in the same session. As such, | |
3438 | IBGP requires a full mesh of all peers. For large networks, this quickly becomes | |
3439 | unscalable. Introducing route reflectors removes the need for the full-mesh. | |
8fcedbd2 | 3440 | |
749afd7d RF |
3441 | When route reflectors are configured, these will reflect the routes announced |
3442 | by the peers configured as clients. A route reflector client is configured | |
3443 | with: | |
8fcedbd2 QY |
3444 | |
3445 | .. index:: neighbor PEER route-reflector-client | |
3446 | .. clicmd:: neighbor PEER route-reflector-client | |
3447 | ||
3d13052d | 3448 | .. index:: neighbor PEER route-reflector-client |
8fcedbd2 | 3449 | .. clicmd:: no neighbor PEER route-reflector-client |
c3c5a71f | 3450 | |
749afd7d RF |
3451 | To avoid single points of failure, multiple route reflectors can be configured. |
3452 | ||
3453 | A cluster is a collection of route reflectors and their clients, and is used | |
3454 | by route reflectors to avoid looping. | |
3455 | ||
3456 | .. index:: bgp cluster-id A.B.C.D | |
3457 | .. clicmd:: bgp cluster-id A.B.C.D | |
42fc5d26 | 3458 | |
3d13052d | 3459 | .. index:: bgp no-rib |
8dad2243 DS |
3460 | .. clicmd:: [no] bgp no-rib |
3461 | ||
3462 | To set and unset the BGP daemon ``-n`` / ``--no_kernel`` options during runtime | |
3463 | to disable BGP route installation to the RIB (Zebra), the ``[no] bgp no-rib`` | |
3464 | commands can be used; | |
3465 | ||
3466 | Please note that setting the option during runtime will withdraw all routes in | |
3467 | the daemons RIB from Zebra and unsetting it will announce all routes in the | |
3468 | daemons RIB to Zebra. If the option is passed as a command line argument when | |
3469 | starting the daemon and the configuration gets saved, the option will persist | |
3470 | unless removed from the configuration with the negating command prior to the | |
3471 | configuration write operation. | |
3472 | ||
9a06c157 DS |
3473 | .. index:: [no] bgp send-extra-data zebra |
3474 | .. clicmd:: [no] bgp send-extra-data zebra | |
3475 | ||
3476 | This Command turns off the ability of BGP to send extra data to zebra. | |
3477 | In this case it's the AS-Path being used for the path. The default behavior | |
3478 | in BGP is to send this data and to turn it off enter the no form of the command. | |
3479 | If extra data was sent to zebra, and this command is turned on there is no | |
3480 | effort to clean up this data in the rib. | |
3481 | ||
1cc55938 S |
3482 | .. _bgp-suppress-fib: |
3483 | ||
3484 | Suppressing routes not installed in FIB | |
3485 | ======================================= | |
3486 | ||
3487 | The FRR implementation of BGP advertises prefixes learnt from a peer to other | |
3488 | peers even if the routes do not get installed in the FIB. There can be | |
3489 | scenarios where the hardware tables in some of the routers (along the path from | |
3490 | the source to destination) is full which will result in all routes not getting | |
3491 | installed in the FIB. If these routes are advertised to the downstream routers | |
3492 | then traffic will start flowing and will be dropped at the intermediate router. | |
3493 | ||
3494 | The solution is to provide a configurable option to check for the FIB install | |
3495 | status of the prefixes and advertise to peers if the prefixes are successfully | |
3496 | installed in the FIB. The advertisement of the prefixes are suppressed if it is | |
3497 | not installed in FIB. | |
3498 | ||
3499 | The following conditions apply will apply when checking for route installation | |
3500 | status in FIB: | |
0ea5223c | 3501 | |
1cc55938 S |
3502 | 1. The advertisement or suppression of routes based on FIB install status |
3503 | applies only for newly learnt routes from peer (routes which are not in | |
3504 | BGP local RIB). | |
3505 | 2. If the route received from peer already exists in BGP local RIB and route | |
3506 | attributes have changed (best path changed), the old path is deleted and | |
3507 | new path is installed in FIB. The FIB install status will not have any | |
3508 | effect. Therefore only when the route is received first time the checks | |
3509 | apply. | |
3510 | 3. The feature will not apply for routes learnt through other means like | |
3511 | redistribution to bgp from other protocols. This is applicable only to | |
3512 | peer learnt routes. | |
3513 | 4. If a route is installed in FIB and then gets deleted from the dataplane, | |
3514 | then routes will not be withdrawn from peers. This will be considered as | |
3515 | dataplane issue. | |
3516 | 5. The feature will slightly increase the time required to advertise the routes | |
3517 | to peers since the route install status needs to be received from the FIB | |
3518 | 6. If routes are received by the peer before the configuration is applied, then | |
3519 | the bgp sessions need to be reset for the configuration to take effect. | |
3520 | 7. If the route which is already installed in dataplane is removed for some | |
3521 | reason, sending withdraw message to peers is not currently supported. | |
3522 | ||
3d13052d | 3523 | .. index:: bgp suppress-fib-pending |
1cc55938 | 3524 | .. clicmd:: [no] bgp suppress-fib-pending |
8dad2243 | 3525 | |
0efdf0fe | 3526 | .. _routing-policy: |
42fc5d26 | 3527 | |
8fcedbd2 QY |
3528 | Routing Policy |
3529 | ============== | |
42fc5d26 | 3530 | |
4da7fda3 | 3531 | You can set different routing policy for a peer. For example, you can set |
9eb95b3b QY |
3532 | different filter for a peer. |
3533 | ||
3534 | .. code-block:: frr | |
c1a54c05 | 3535 | |
c1a54c05 QY |
3536 | ! |
3537 | router bgp 1 view 1 | |
3538 | neighbor 10.0.0.1 remote-as 2 | |
3539 | address-family ipv4 unicast | |
3540 | neighbor 10.0.0.1 distribute-list 1 in | |
3541 | exit-address-family | |
3542 | ! | |
3543 | router bgp 1 view 2 | |
3544 | neighbor 10.0.0.1 remote-as 2 | |
3545 | address-family ipv4 unicast | |
3546 | neighbor 10.0.0.1 distribute-list 2 in | |
3547 | exit-address-family | |
c3c5a71f | 3548 | |
4da7fda3 QY |
3549 | This means BGP update from a peer 10.0.0.1 goes to both BGP view 1 and view 2. |
3550 | When the update is inserted into view 1, distribute-list 1 is applied. On the | |
3551 | other hand, when the update is inserted into view 2, distribute-list 2 is | |
3552 | applied. | |
42fc5d26 | 3553 | |
42fc5d26 | 3554 | |
0efdf0fe | 3555 | .. _bgp-regular-expressions: |
42fc5d26 QY |
3556 | |
3557 | BGP Regular Expressions | |
3558 | ======================= | |
3559 | ||
8fcedbd2 QY |
3560 | BGP regular expressions are based on :t:`POSIX 1003.2` regular expressions. The |
3561 | following description is just a quick subset of the POSIX regular expressions. | |
42fc5d26 QY |
3562 | |
3563 | ||
8fcedbd2 | 3564 | .\* |
c1a54c05 | 3565 | Matches any single character. |
42fc5d26 | 3566 | |
8fcedbd2 | 3567 | \* |
c1a54c05 | 3568 | Matches 0 or more occurrences of pattern. |
42fc5d26 | 3569 | |
8fcedbd2 | 3570 | \+ |
c1a54c05 | 3571 | Matches 1 or more occurrences of pattern. |
42fc5d26 QY |
3572 | |
3573 | ? | |
c1a54c05 | 3574 | Match 0 or 1 occurrences of pattern. |
42fc5d26 QY |
3575 | |
3576 | ^ | |
c1a54c05 | 3577 | Matches the beginning of the line. |
42fc5d26 QY |
3578 | |
3579 | $ | |
c1a54c05 | 3580 | Matches the end of the line. |
42fc5d26 QY |
3581 | |
3582 | _ | |
8fcedbd2 QY |
3583 | The ``_`` character has special meanings in BGP regular expressions. It |
3584 | matches to space and comma , and AS set delimiter ``{`` and ``}`` and AS | |
3585 | confederation delimiter ``(`` and ``)``. And it also matches to the | |
3586 | beginning of the line and the end of the line. So ``_`` can be used for AS | |
3587 | value boundaries match. This character technically evaluates to | |
3588 | ``(^|[,{}()]|$)``. | |
42fc5d26 | 3589 | |
42fc5d26 | 3590 | |
c1a54c05 | 3591 | .. _bgp-configuration-examples: |
42fc5d26 | 3592 | |
8fcedbd2 QY |
3593 | Miscellaneous Configuration Examples |
3594 | ==================================== | |
42fc5d26 | 3595 | |
9eb95b3b QY |
3596 | Example of a session to an upstream, advertising only one prefix to it. |
3597 | ||
3598 | .. code-block:: frr | |
42fc5d26 | 3599 | |
c1a54c05 QY |
3600 | router bgp 64512 |
3601 | bgp router-id 10.236.87.1 | |
3602 | neighbor upstream peer-group | |
3603 | neighbor upstream remote-as 64515 | |
3604 | neighbor upstream capability dynamic | |
3605 | neighbor 10.1.1.1 peer-group upstream | |
3606 | neighbor 10.1.1.1 description ACME ISP | |
c3c5a71f | 3607 | |
c1a54c05 QY |
3608 | address-family ipv4 unicast |
3609 | network 10.236.87.0/24 | |
3610 | neighbor upstream prefix-list pl-allowed-adv out | |
3611 | exit-address-family | |
3612 | ! | |
3613 | ip prefix-list pl-allowed-adv seq 5 permit 82.195.133.0/25 | |
3614 | ip prefix-list pl-allowed-adv seq 10 deny any | |
42fc5d26 | 3615 | |
aa9eafa4 QY |
3616 | A more complex example including upstream, peer and customer sessions |
3617 | advertising global prefixes and NO_EXPORT prefixes and providing actions for | |
3618 | customer routes based on community values. Extensive use is made of route-maps | |
3619 | and the 'call' feature to support selective advertising of prefixes. This | |
3620 | example is intended as guidance only, it has NOT been tested and almost | |
3621 | certainly contains silly mistakes, if not serious flaws. | |
42fc5d26 | 3622 | |
9eb95b3b | 3623 | .. code-block:: frr |
42fc5d26 | 3624 | |
c1a54c05 QY |
3625 | router bgp 64512 |
3626 | bgp router-id 10.236.87.1 | |
3627 | neighbor upstream capability dynamic | |
3628 | neighbor cust capability dynamic | |
3629 | neighbor peer capability dynamic | |
3630 | neighbor 10.1.1.1 remote-as 64515 | |
3631 | neighbor 10.1.1.1 peer-group upstream | |
3632 | neighbor 10.2.1.1 remote-as 64516 | |
3633 | neighbor 10.2.1.1 peer-group upstream | |
3634 | neighbor 10.3.1.1 remote-as 64517 | |
3635 | neighbor 10.3.1.1 peer-group cust-default | |
3636 | neighbor 10.3.1.1 description customer1 | |
3637 | neighbor 10.4.1.1 remote-as 64518 | |
3638 | neighbor 10.4.1.1 peer-group cust | |
3639 | neighbor 10.4.1.1 description customer2 | |
3640 | neighbor 10.5.1.1 remote-as 64519 | |
3641 | neighbor 10.5.1.1 peer-group peer | |
3642 | neighbor 10.5.1.1 description peer AS 1 | |
3643 | neighbor 10.6.1.1 remote-as 64520 | |
3644 | neighbor 10.6.1.1 peer-group peer | |
3645 | neighbor 10.6.1.1 description peer AS 2 | |
3646 | ||
3647 | address-family ipv4 unicast | |
3648 | network 10.123.456.0/24 | |
3649 | network 10.123.456.128/25 route-map rm-no-export | |
3650 | neighbor upstream route-map rm-upstream-out out | |
3651 | neighbor cust route-map rm-cust-in in | |
3652 | neighbor cust route-map rm-cust-out out | |
3653 | neighbor cust send-community both | |
3654 | neighbor peer route-map rm-peer-in in | |
3655 | neighbor peer route-map rm-peer-out out | |
3656 | neighbor peer send-community both | |
3657 | neighbor 10.3.1.1 prefix-list pl-cust1-network in | |
3658 | neighbor 10.4.1.1 prefix-list pl-cust2-network in | |
3659 | neighbor 10.5.1.1 prefix-list pl-peer1-network in | |
3660 | neighbor 10.6.1.1 prefix-list pl-peer2-network in | |
3661 | exit-address-family | |
3662 | ! | |
3663 | ip prefix-list pl-default permit 0.0.0.0/0 | |
3664 | ! | |
3665 | ip prefix-list pl-upstream-peers permit 10.1.1.1/32 | |
3666 | ip prefix-list pl-upstream-peers permit 10.2.1.1/32 | |
3667 | ! | |
3668 | ip prefix-list pl-cust1-network permit 10.3.1.0/24 | |
3669 | ip prefix-list pl-cust1-network permit 10.3.2.0/24 | |
3670 | ! | |
3671 | ip prefix-list pl-cust2-network permit 10.4.1.0/24 | |
3672 | ! | |
3673 | ip prefix-list pl-peer1-network permit 10.5.1.0/24 | |
3674 | ip prefix-list pl-peer1-network permit 10.5.2.0/24 | |
3675 | ip prefix-list pl-peer1-network permit 192.168.0.0/24 | |
3676 | ! | |
3677 | ip prefix-list pl-peer2-network permit 10.6.1.0/24 | |
3678 | ip prefix-list pl-peer2-network permit 10.6.2.0/24 | |
3679 | ip prefix-list pl-peer2-network permit 192.168.1.0/24 | |
3680 | ip prefix-list pl-peer2-network permit 192.168.2.0/24 | |
3681 | ip prefix-list pl-peer2-network permit 172.16.1/24 | |
3682 | ! | |
9b6fddd4 DS |
3683 | bgp as-path access-list asp-own-as permit ^$ |
3684 | bgp as-path access-list asp-own-as permit _64512_ | |
c1a54c05 QY |
3685 | ! |
3686 | ! ################################################################# | |
3687 | ! Match communities we provide actions for, on routes receives from | |
3688 | ! customers. Communities values of <our-ASN>:X, with X, have actions: | |
3689 | ! | |
3690 | ! 100 - blackhole the prefix | |
3691 | ! 200 - set no_export | |
3692 | ! 300 - advertise only to other customers | |
3693 | ! 400 - advertise only to upstreams | |
3694 | ! 500 - set no_export when advertising to upstreams | |
3695 | ! 2X00 - set local_preference to X00 | |
3696 | ! | |
3697 | ! blackhole the prefix of the route | |
a64e0ee5 | 3698 | bgp community-list standard cm-blackhole permit 64512:100 |
c1a54c05 QY |
3699 | ! |
3700 | ! set no-export community before advertising | |
a64e0ee5 | 3701 | bgp community-list standard cm-set-no-export permit 64512:200 |
c1a54c05 QY |
3702 | ! |
3703 | ! advertise only to other customers | |
a64e0ee5 | 3704 | bgp community-list standard cm-cust-only permit 64512:300 |
c1a54c05 QY |
3705 | ! |
3706 | ! advertise only to upstreams | |
a64e0ee5 | 3707 | bgp community-list standard cm-upstream-only permit 64512:400 |
c1a54c05 QY |
3708 | ! |
3709 | ! advertise to upstreams with no-export | |
a64e0ee5 | 3710 | bgp community-list standard cm-upstream-noexport permit 64512:500 |
c1a54c05 QY |
3711 | ! |
3712 | ! set local-pref to least significant 3 digits of the community | |
a64e0ee5 DA |
3713 | bgp community-list standard cm-prefmod-100 permit 64512:2100 |
3714 | bgp community-list standard cm-prefmod-200 permit 64512:2200 | |
3715 | bgp community-list standard cm-prefmod-300 permit 64512:2300 | |
3716 | bgp community-list standard cm-prefmod-400 permit 64512:2400 | |
3717 | bgp community-list expanded cme-prefmod-range permit 64512:2... | |
c1a54c05 QY |
3718 | ! |
3719 | ! Informational communities | |
3720 | ! | |
3721 | ! 3000 - learned from upstream | |
3722 | ! 3100 - learned from customer | |
3723 | ! 3200 - learned from peer | |
3724 | ! | |
a64e0ee5 DA |
3725 | bgp community-list standard cm-learnt-upstream permit 64512:3000 |
3726 | bgp community-list standard cm-learnt-cust permit 64512:3100 | |
3727 | bgp community-list standard cm-learnt-peer permit 64512:3200 | |
c1a54c05 QY |
3728 | ! |
3729 | ! ################################################################### | |
3730 | ! Utility route-maps | |
3731 | ! | |
3732 | ! These utility route-maps generally should not used to permit/deny | |
3733 | ! routes, i.e. they do not have meaning as filters, and hence probably | |
3734 | ! should be used with 'on-match next'. These all finish with an empty | |
3735 | ! permit entry so as not interfere with processing in the caller. | |
3736 | ! | |
3737 | route-map rm-no-export permit 10 | |
3738 | set community additive no-export | |
3739 | route-map rm-no-export permit 20 | |
3740 | ! | |
3741 | route-map rm-blackhole permit 10 | |
f6aa36f5 | 3742 | description blackhole, up-pref and ensure it cannot escape this AS |
c1a54c05 QY |
3743 | set ip next-hop 127.0.0.1 |
3744 | set local-preference 10 | |
3745 | set community additive no-export | |
3746 | route-map rm-blackhole permit 20 | |
3747 | ! | |
3748 | ! Set local-pref as requested | |
3749 | route-map rm-prefmod permit 10 | |
3750 | match community cm-prefmod-100 | |
3751 | set local-preference 100 | |
3752 | route-map rm-prefmod permit 20 | |
3753 | match community cm-prefmod-200 | |
3754 | set local-preference 200 | |
3755 | route-map rm-prefmod permit 30 | |
3756 | match community cm-prefmod-300 | |
3757 | set local-preference 300 | |
3758 | route-map rm-prefmod permit 40 | |
3759 | match community cm-prefmod-400 | |
3760 | set local-preference 400 | |
3761 | route-map rm-prefmod permit 50 | |
3762 | ! | |
3763 | ! Community actions to take on receipt of route. | |
3764 | route-map rm-community-in permit 10 | |
3765 | description check for blackholing, no point continuing if it matches. | |
3766 | match community cm-blackhole | |
3767 | call rm-blackhole | |
3768 | route-map rm-community-in permit 20 | |
3769 | match community cm-set-no-export | |
3770 | call rm-no-export | |
3771 | on-match next | |
3772 | route-map rm-community-in permit 30 | |
3773 | match community cme-prefmod-range | |
3774 | call rm-prefmod | |
3775 | route-map rm-community-in permit 40 | |
3776 | ! | |
3777 | ! ##################################################################### | |
3778 | ! Community actions to take when advertising a route. | |
3779 | ! These are filtering route-maps, | |
3780 | ! | |
3781 | ! Deny customer routes to upstream with cust-only set. | |
3782 | route-map rm-community-filt-to-upstream deny 10 | |
3783 | match community cm-learnt-cust | |
3784 | match community cm-cust-only | |
3785 | route-map rm-community-filt-to-upstream permit 20 | |
3786 | ! | |
3787 | ! Deny customer routes to other customers with upstream-only set. | |
3788 | route-map rm-community-filt-to-cust deny 10 | |
3789 | match community cm-learnt-cust | |
3790 | match community cm-upstream-only | |
3791 | route-map rm-community-filt-to-cust permit 20 | |
3792 | ! | |
3793 | ! ################################################################### | |
3794 | ! The top-level route-maps applied to sessions. Further entries could | |
3795 | ! be added obviously.. | |
3796 | ! | |
3797 | ! Customers | |
3798 | route-map rm-cust-in permit 10 | |
3799 | call rm-community-in | |
3800 | on-match next | |
3801 | route-map rm-cust-in permit 20 | |
3802 | set community additive 64512:3100 | |
3803 | route-map rm-cust-in permit 30 | |
3804 | ! | |
3805 | route-map rm-cust-out permit 10 | |
3806 | call rm-community-filt-to-cust | |
3807 | on-match next | |
3808 | route-map rm-cust-out permit 20 | |
3809 | ! | |
3810 | ! Upstream transit ASes | |
3811 | route-map rm-upstream-out permit 10 | |
3812 | description filter customer prefixes which are marked cust-only | |
3813 | call rm-community-filt-to-upstream | |
3814 | on-match next | |
3815 | route-map rm-upstream-out permit 20 | |
3816 | description only customer routes are provided to upstreams/peers | |
3817 | match community cm-learnt-cust | |
3818 | ! | |
3819 | ! Peer ASes | |
3820 | ! outbound policy is same as for upstream | |
3821 | route-map rm-peer-out permit 10 | |
3822 | call rm-upstream-out | |
3823 | ! | |
3824 | route-map rm-peer-in permit 10 | |
3825 | set community additive 64512:3200 | |
c3c5a71f | 3826 | |
8fcedbd2 QY |
3827 | |
3828 | Example of how to set up a 6-Bone connection. | |
3829 | ||
3830 | .. code-block:: frr | |
3831 | ||
3832 | ! bgpd configuration | |
3833 | ! ================== | |
3834 | ! | |
3835 | ! MP-BGP configuration | |
3836 | ! | |
3837 | router bgp 7675 | |
3838 | bgp router-id 10.0.0.1 | |
3839 | neighbor 3ffe:1cfa:0:2:2a0:c9ff:fe9e:f56 remote-as `as-number` | |
3840 | ! | |
3841 | address-family ipv6 | |
3842 | network 3ffe:506::/32 | |
3843 | neighbor 3ffe:1cfa:0:2:2a0:c9ff:fe9e:f56 activate | |
3844 | neighbor 3ffe:1cfa:0:2:2a0:c9ff:fe9e:f56 route-map set-nexthop out | |
3845 | neighbor 3ffe:1cfa:0:2:2c0:4fff:fe68:a231 remote-as `as-number` | |
3846 | neighbor 3ffe:1cfa:0:2:2c0:4fff:fe68:a231 route-map set-nexthop out | |
3847 | exit-address-family | |
3848 | ! | |
3849 | ipv6 access-list all permit any | |
3850 | ! | |
3851 | ! Set output nexthop address. | |
3852 | ! | |
3853 | route-map set-nexthop permit 10 | |
3854 | match ipv6 address all | |
3855 | set ipv6 nexthop global 3ffe:1cfa:0:2:2c0:4fff:fe68:a225 | |
3856 | set ipv6 nexthop local fe80::2c0:4fff:fe68:a225 | |
3857 | ! | |
3858 | log file bgpd.log | |
3859 | ! | |
3860 | ||
3861 | ||
9e146a81 | 3862 | .. include:: routeserver.rst |
f3817860 QY |
3863 | |
3864 | .. include:: rpki.rst | |
c1a54c05 | 3865 | |
ed647ed2 | 3866 | .. include:: wecmp_linkbw.rst |
3867 | ||
00458d01 PG |
3868 | .. include:: flowspec.rst |
3869 | ||
d1e7591e | 3870 | .. [#med-transitivity-rant] For some set of objects to have an order, there *must* be some binary ordering relation that is defined for *every* combination of those objects, and that relation *must* be transitive. I.e.:, if the relation operator is <, and if a < b and b < c then that relation must carry over and it *must* be that a < c for the objects to have an order. The ordering relation may allow for equality, i.e. a < b and b < a may both be true and imply that a and b are equal in the order and not distinguished by it, in which case the set has a partial order. Otherwise, if there is an order, all the objects have a distinct place in the order and the set has a total order) |
c1a54c05 QY |
3871 | .. [bgp-route-osci-cond] McPherson, D. and Gill, V. and Walton, D., "Border Gateway Protocol (BGP) Persistent Route Oscillation Condition", IETF RFC3345 |
3872 | .. [stable-flexible-ibgp] Flavel, A. and M. Roughan, "Stable and flexible iBGP", ACM SIGCOMM 2009 | |
3873 | .. [ibgp-correctness] Griffin, T. and G. Wilfong, "On the correctness of IBGP configuration", ACM SIGCOMM 2002 |