7 RIP -- Routing Information Protocol is widely deployed interior gateway
8 protocol. RIP was developed in the 1970s at Xerox Labs as part of the
9 XNS routing protocol. RIP is a :term:`distance-vector` protocol and is
10 based on the :term:`Bellman-Ford` algorithms. As a distance-vector
11 protocol, RIP router send updates to its neighbors periodically, thus
12 allowing the convergence to a known topology. In each update, the
13 distance to any given network will be broadcast to its neighboring
16 *ripd* supports RIP version 2 as described in RFC2453 and RIP
17 version 1 as described in RFC1058.
19 .. _starting-and-stopping-ripd:
21 Starting and Stopping ripd
22 ==========================
24 The default configuration file name of *ripd*'s is :file:`ripd.conf`. When
25 invocation *ripd* searches directory |INSTALL_PREFIX_ETC|. If :file:`ripd.conf`
26 is not there next search current directory.
28 RIP uses UDP port 520 to send and receive RIP packets. So the user must have
29 the capability to bind the port, generally this means that the user must have
30 superuser privileges. RIP protocol requires interface information maintained by
31 *zebra* daemon. So running *zebra* is mandatory to run *ripd*. Thus minimum
32 sequence for running RIP is like below:
40 Please note that *zebra* must be invoked before *ripd*.
42 To stop *ripd*. Please use::
43 kill `cat /var/run/ripd.pid`
45 Certain signals have special meanings to *ripd*.
47 +-------------+------------------------------------------------------+
49 +=============+======================================================+
50 | ``SIGHUP`` | Reload configuration file :file:`ripd.conf`. |
51 | | All configurations are reset. All routes learned |
52 | | so far are cleared and removed from routing table. |
53 +-------------+------------------------------------------------------+
54 | ``SIGUSR1`` | Rotate the *ripd* logfile. |
55 +-------------+------------------------------------------------------+
57 | ``SIGTERM`` | Sweep all installed routes and gracefully terminate. |
58 +-------------+------------------------------------------------------+
60 *ripd* invocation options. Common options that can be specified
61 (:ref:`common-invocation-options`).
69 The netmask features of *ripd* support both version 1 and version 2 of RIP.
70 Version 1 of RIP originally contained no netmask information. In RIP version 1,
71 network classes were originally used to determine the size of the netmask.
72 Class A networks use 8 bits of mask, Class B networks use 16 bits of masks,
73 while Class C networks use 24 bits of mask. Today, the most widely used method
74 of a network mask is assigned to the packet on the basis of the interface that
75 received the packet. Version 2 of RIP supports a variable length subnet mask
76 (VLSM). By extending the subnet mask, the mask can be divided and reused. Each
77 subnet can be used for different purposes such as large to middle size LANs and
78 WAN links. FRR *ripd* does not support the non-sequential netmasks that are
79 included in RIP Version 2.
81 In a case of similar information with the same prefix and metric, the old
82 information will be suppressed. Ripd does not currently support equal cost
85 .. _rip-configuration:
90 .. clicmd:: router rip
92 The `router rip` command is necessary to enable RIP. To disable RIP, use the
93 `no router rip` command. RIP must be enabled before carrying out any of the
99 .. clicmd:: network NETWORK
102 Set the RIP enable interface by NETWORK. The interfaces which have addresses
103 matching with NETWORK are enabled.
105 This group of commands either enables or disables RIP interfaces between
106 certain numbers of a specified network address. For example, if the network
107 for 10.0.0.0/24 is RIP enabled, this would result in all the addresses from
108 10.0.0.0 to 10.0.0.255 being enabled for RIP. The `no network` command will
109 disable RIP for the specified network.
111 .. clicmd:: network IFNAME
114 Set a RIP enabled interface by IFNAME. Both the sending and
115 receiving of RIP packets will be enabled on the port specified in the
116 `network ifname` command. The `no network ifname` command will disable
117 RIP on the specified interface.
119 .. clicmd:: neighbor A.B.C.D
122 Specify RIP neighbor. When a neighbor doesn't understand multicast, this
123 command is used to specify neighbors. In some cases, not all routers will be
124 able to understand multicasting, where packets are sent to a network or a
125 group of addresses. In a situation where a neighbor cannot process multicast
126 packets, it is necessary to establish a direct link between routers. The
127 neighbor command allows the network administrator to specify a router as a
128 RIP neighbor. The `no neighbor a.b.c.d` command will disable the RIP
131 Below is very simple RIP configuration. Interface `eth0` and interface which
132 address match to `10.0.0.0/8` are RIP enabled.
143 .. clicmd:: passive-interface (IFNAME|default)
146 This command sets the specified interface to passive mode. On passive mode
147 interface, all receiving packets are processed as normal and ripd does not
148 send either multicast or unicast RIP packets except to RIP neighbors
149 specified with `neighbor` command. The interface may be specified as
150 `default` to make ripd default to passive on all interfaces.
152 The default is to be passive on all interfaces.
154 .. clicmd:: ip split-horizon
157 Control split-horizon on the interface. Default is `ip split-horizon`. If
158 you don't perform split-horizon on the interface, please specify `no ip
161 .. _rip-version-control:
166 RIP can be configured to send either Version 1 or Version 2 packets. The
167 default is to send RIPv2 while accepting both RIPv1 and RIPv2 (and replying
168 with packets of the appropriate version for REQUESTS / triggered updates). The
169 version to receive and send can be specified globally, and further overridden on
170 a per-interface basis if needs be for send and receive separately (see below).
172 It is important to note that RIPv1 cannot be authenticated. Further, if RIPv1
173 is enabled then RIP will reply to REQUEST packets, sending the state of its RIP
174 routing table to any remote routers that ask on demand. For a more detailed
175 discussion on the security implications of RIPv1 see :ref:`rip-authentication`.
177 .. clicmd:: version VERSION
179 Set RIP version to accept for reads and send. ``VERSION`` can be either 1 or
182 Disabling RIPv1 by specifying version 2 is STRONGLY encouraged,
183 :ref:`rip-authentication`. This may become the default in a future release.
185 Default: Send Version 2, and accept either version.
187 .. clicmd:: ip rip send version VERSION
189 VERSION can be ``1``, ``2``, or ``1 2``.
191 This interface command overrides the global rip version setting, and selects
192 which version of RIP to send packets with, for this interface specifically.
193 Choice of RIP Version 1, RIP Version 2, or both versions. In the latter
194 case, where ``1 2`` is specified, packets will be both broadcast and
197 Default: Send packets according to the global version (version 2)
199 .. clicmd:: ip rip receive version VERSION
201 VERSION can be ``1``, ``2``, or ``1 2``.
203 This interface command overrides the global rip version setting, and selects
204 which versions of RIP packets will be accepted on this interface. Choice of
205 RIP Version 1, RIP Version 2, or both.
207 Default: Accept packets according to the global setting (both 1 and 2).
210 .. _how-to-announce-rip-route:
212 How to Announce RIP route
213 =========================
215 .. clicmd:: redistribute <babel|bgp|connected|eigrp|isis|kernel|openfabric|ospf|sharp|static|table> [metric (0-16)] [route-map WORD]
217 Redistribute routes from other sources into RIP.
219 If you want to specify RIP only static routes:
221 .. clicmd:: default-information originate
223 .. clicmd:: route A.B.C.D/M
226 This command is specific to FRR. The `route` command makes a static route
227 only inside RIP. This command should be used only by advanced users who are
228 particularly knowledgeable about the RIP protocol. In most cases, we
229 recommend creating a static route in FRR and redistributing it in RIP using
230 `redistribute static`.
232 .. _filtering-rip-routes:
237 RIP routes can be filtered by a distribute-list.
239 .. clicmd:: distribute-list ACCESS_LIST DIRECT IFNAME
241 You can apply access lists to the interface with a `distribute-list` command.
242 ACCESS_LIST is the access list name. DIRECT is ``in`` or ``out``. If DIRECT
243 is ``in`` the access list is applied to input packets.
245 The `distribute-list` command can be used to filter the RIP path.
246 `distribute-list` can apply access-lists to a chosen interface. First, one
247 should specify the access-list. Next, the name of the access-list is used in
248 the distribute-list command. For example, in the following configuration
249 ``eth0`` will permit only the paths that match the route 10.0.0.0/8
255 distribute-list private in eth0
257 access-list private permit 10 10.0.0.0/8
258 access-list private deny any
262 `distribute-list` can be applied to both incoming and outgoing data.
264 .. clicmd:: distribute-list prefix PREFIX_LIST (in|out) IFNAME
266 You can apply prefix lists to the interface with a `distribute-list`
267 command. PREFIX_LIST is the prefix list name. Next is the direction of
268 ``in`` or ``out``. If DIRECT is ``in`` the access list is applied to input
271 .. _rip-metric-manipulation:
273 RIP Metric Manipulation
274 =======================
276 RIP metric is a value for distance for the network. Usually
277 *ripd* increment the metric when the network information is
278 received. Redistributed routes' metric is set to 1.
280 .. clicmd:: default-metric (1-16)
283 This command modifies the default metric value for redistributed routes.
284 The default value is 1. This command does not affect connected route even if
285 it is redistributed by *redistribute connected*. To modify connected route's
286 metric value, please use ``redistribute connected metric`` or *route-map*.
287 *offset-list* also affects connected routes.
289 .. clicmd:: offset-list ACCESS-LIST (in|out)
291 .. clicmd:: offset-list ACCESS-LIST (in|out) IFNAME
299 Distance value is used in zebra daemon. Default RIP distance is 120.
301 .. clicmd:: distance (1-255)
304 Set default RIP distance to specified value.
306 .. clicmd:: distance (1-255) A.B.C.D/M
309 Set default RIP distance to specified value when the route's source IP
310 address matches the specified prefix.
312 .. clicmd:: distance (1-255) A.B.C.D/M ACCESS-LIST
315 Set default RIP distance to specified value when the route's source IP
316 address matches the specified prefix and the specified access-list.
323 Usage of *ripd*'s route-map support.
325 Optional argument route-map MAP_NAME can be added to each `redistribute`
330 redistribute static [route-map MAP_NAME]
331 redistribute connected [route-map MAP_NAME]
335 Cisco applies route-map _before_ routes will exported to rip route table. In
336 current FRR's test implementation, *ripd* applies route-map after routes are
337 listed in the route table and before routes will be announced to an interface
338 (something like output filter). I think it is not so clear, but it is draft and
339 it may be changed at future.
341 Route-map statement (:ref:`route-map`) is needed to use route-map
344 .. clicmd:: match interface WORD
346 This command match to incoming interface. Notation of this match is
347 different from Cisco. Cisco uses a list of interfaces - NAME1 NAME2 ...
348 NAMEN. Ripd allows only one name (maybe will change in the future). Next -
349 Cisco means interface which includes next-hop of routes (it is somewhat
350 similar to "ip next-hop" statement). Ripd means interface where this route
351 will be sent. This difference is because "next-hop" of same routes which
352 sends to different interfaces must be different. Maybe it'd be better to
353 made new matches - say "match interface-out NAME" or something like that.
355 .. clicmd:: match ip address WORD
357 .. clicmd:: match ip address prefix-list WORD
359 Match if route destination is permitted by access-list.
361 .. clicmd:: match ip next-hop WORD
363 .. clicmd:: match ip next-hop prefix-list WORD
365 Match if route next-hop (meaning next-hop listed in the rip route-table as
366 displayed by "show ip rip") is permitted by access-list.
368 .. clicmd:: match metric (0-4294967295)
370 This command match to the metric value of RIP updates. For other protocol
371 compatibility metric range is shown as (0-4294967295). But for RIP protocol
372 only the value range (0-16) make sense.
374 .. clicmd:: set ip next-hop A.B.C.D
376 This command set next hop value in RIPv2 protocol. This command does not
377 affect RIPv1 because there is no next hop field in the packet.
379 .. clicmd:: set metric (0-4294967295)
381 Set a metric for matched route when sending announcement. The metric value
382 range is very large for compatibility with other protocols. For RIP, valid
383 metric values are from 1 to 16.
385 .. _rip-authentication:
390 RIPv2 allows packets to be authenticated via either an insecure plain
391 text password, included with the packet, or via a more secure MD5 based
392 :abbr:`HMAC (keyed-Hashing for Message AuthentiCation)`,
393 RIPv1 can not be authenticated at all, thus when authentication is
394 configured `ripd` will discard routing updates received via RIPv1
397 However, unless RIPv1 reception is disabled entirely,
398 :ref:`rip-version-control`, RIPv1 REQUEST packets which are received,
399 which query the router for routing information, will still be honoured
400 by `ripd`, and `ripd` WILL reply to such packets. This allows
401 `ripd` to honour such REQUESTs (which sometimes is used by old
402 equipment and very simple devices to bootstrap their default route),
403 while still providing security for route updates which are received.
405 In short: Enabling authentication prevents routes being updated by
406 unauthenticated remote routers, but still can allow routes (I.e. the
407 entire RIP routing table) to be queried remotely, potentially by anyone
408 on the internet, via RIPv1.
410 To prevent such unauthenticated querying of routes disable RIPv1,
411 :ref:`rip-version-control`.
413 .. clicmd:: ip rip authentication mode md5
416 Set the interface with RIPv2 MD5 authentication.
418 .. clicmd:: ip rip authentication mode text
421 Set the interface with RIPv2 simple password authentication.
423 .. clicmd:: ip rip authentication string STRING
426 RIP version 2 has simple text authentication. This command sets
427 authentication string. The string must be shorter than 16 characters.
429 .. clicmd:: ip rip authentication key-chain KEY-CHAIN
432 Specify Keyed MD5 chain.
442 ip rip authentication mode md5
443 ip rip authentication key-chain test
452 .. clicmd:: timers basic UPDATE TIMEOUT GARBAGE
455 RIP protocol has several timers. User can configure those timers' values
456 by `timers basic` command.
458 The default settings for the timers are as follows:
460 - The update timer is 30 seconds. Every update timer seconds, the RIP
461 process is awakened to send an unsolicited Response message containing
462 the complete routing table to all neighboring RIP routers.
463 - The timeout timer is 180 seconds. Upon expiration of the timeout, the
464 route is no longer valid; however, it is retained in the routing table
465 for a short time so that neighbors can be notified that the route has
467 - The garbage collect timer is 120 seconds. Upon expiration of the
468 garbage-collection timer, the route is finally removed from the routing
471 The ``timers basic`` command allows the the default values of the timers
472 listed above to be changed.
475 .. _show-rip-information:
480 To display RIP routes.
482 .. clicmd:: show ip rip
486 The command displays all RIP routes. For routes that are received
487 through RIP, this command will display the time the packet was sent and
488 the tag information. This command will also display this information
489 for routes redistributed into RIP.
491 .. clicmd:: show ip rip status
493 The command displays current RIP status. It includes RIP timer,
494 filtering, version, RIP enabled interface and RIP peer information.
498 ripd> **show ip rip status**
499 Routing Protocol is "rip"
500 Sending updates every 30 seconds with +/-50%, next due in 35 seconds
501 Timeout after 180 seconds, garbage collect after 120 seconds
502 Outgoing update filter list for all interface is not set
503 Incoming update filter list for all interface is not set
504 Default redistribution metric is 1
505 Redistributing: kernel connected
506 Default version control: send version 2, receive version 2
508 Routing for Networks:
513 Routing Information Sources:
514 Gateway BadPackets BadRoutes Distance Last Update
520 Debug for RIP protocol.
522 .. clicmd:: debug rip events
524 Shows RIP events. Sending and receiving packets, timers, and changes in
525 interfaces are events shown with *ripd*.
527 .. clicmd:: debug rip packet
529 Shows display detailed information about the RIP packets. The origin and
530 port number of the packet as well as a packet dump is shown.
532 .. clicmd:: debug rip zebra
534 This command will show the communication between *ripd* and *zebra*. The
535 main information will include addition and deletion of paths to the kernel
536 and the sending and receiving of interface information.
538 .. clicmd:: show debugging rip
540 Shows all information currently set for ripd debug.