doc/user/isisd.rst

   1 .. _isis:
   2
   3 ****
   4 ISIS
   5 ****
   6
   7 :abbr:`ISIS (Intermediate System to Intermediate System)` is a routing protocol
   8 which is described in :t:`ISO10589`, :rfc:`1195`, :rfc:`5308`. ISIS is an
   9 :abbr:`IGP (Interior Gateway Protocol)`. Compared with :abbr:`RIP`,
  10 :abbr:`ISIS` can provide scalable network support and faster convergence times
  11 like :abbr:`OSPF`. ISIS is widely used in large networks such as :abbr:`ISP
  12 (Internet Service Provider)` and carrier backbone networks.
  13
  14 .. _configuring-isisd:
  15
  16 Configuring isisd
  17 =================
  18
  19 There are no *isisd* specific options. Common options can be specified
  20 (:ref:`common-invocation-options`) to *isisd*. *isisd* needs to acquire
  21 interface information from *zebra* in order to function. Therefore *zebra* must
  22 be running before invoking *isisd*. Also, if *zebra* is restarted then *isisd*
  23 must be too.
  24
  25 Like other daemons, *isisd* configuration is done in :abbr:`ISIS` specific
  26 configuration file :file:`isisd.conf`.
  27
  28 .. _isis-router:
  29
  30 ISIS router
  31 ===========
  32
  33 To start the ISIS process you have to specify the ISIS router. As of this
  34 writing, *isisd* does not support multiple ISIS processes.
  35
  36 .. clicmd:: router isis WORD [vrf NAME]
  37
  38    Enable or disable the ISIS process by specifying the ISIS domain with
  39    'WORD'.  *isisd* does not yet support multiple ISIS processes but you must
  40    specify the name of ISIS process. The ISIS process name 'WORD' is then used
  41    for interface (see command :clicmd:`ip router isis WORD`).
  42
  43 .. clicmd:: net XX.XXXX. ... .XXX.XX
  44
  45    Set/Unset network entity title (NET) provided in ISO format.
  46
  47 .. clicmd:: hostname dynamic
  48
  49    Enable support for dynamic hostname.
  50
  51 .. clicmd:: area-password [clear | md5] <password>
  52
  53 .. clicmd:: domain-password [clear | md5] <password>
  54
  55    Configure the authentication password for an area, respectively a domain, as
  56    clear text or md5 one.
  57
  58 .. clicmd:: attached-bit [receive ignore | send]
  59
  60    Set attached bit for inter-area traffic:
  61
  62    - receive
  63      If LSP received with attached bit set, create default route to neighbor
  64    - send
  65      If L1|L2 router, set attached bit in LSP sent to L1 router
  66
  67 .. clicmd:: log-adjacency-changes
  68
  69    Log changes in adjacency state.
  70
  71 .. clicmd:: metric-style [narrow | transition | wide]
  72
  73    Set old-style (ISO 10589) or new-style packet formats:
  74
  75    - narrow
  76      Use old style of TLVs with narrow metric
  77    - transition
  78      Send and accept both styles of TLVs during transition
  79    - wide
  80      Use new style of TLVs to carry wider metric. FRR uses this as a default value
  81
  82 .. clicmd:: set-overload-bit
  83
  84    Set overload bit to avoid any transit traffic.
  85
  86 .. clicmd:: purge-originator
  87
  88    Enable or disable :rfc:`6232` purge originator identification.
  89
  90 .. clicmd:: lsp-mtu (128-4352)
  91
  92    Configure the maximum size of generated LSPs, in bytes.
  93
  94
  95 .. _isis-timer:
  96
  97 ISIS Timer
  98 ==========
  99
 100 .. clicmd:: lsp-gen-interval [level-1 | level-2] (1-120)
 101
 102    Set minimum interval in seconds between regenerating same LSP,
 103    globally, for an area (level-1) or a domain (level-2).
 104
 105 .. clicmd:: lsp-refresh-interval [level-1 | level-2] (1-65235)
 106
 107    Set LSP refresh interval in seconds, globally, for an area (level-1) or a
 108    domain (level-2).
 109
 110 .. clicmd:: max-lsp-lifetime [level-1 | level-2] (360-65535)
 111
 112    Set LSP maximum LSP lifetime in seconds, globally, for an area (level-1) or
 113    a domain (level-2).
 114
 115 .. clicmd:: spf-interval [level-1 | level-2] (1-120)
 116
 117    Set minimum interval between consecutive SPF calculations in seconds.
 118
 119 .. _isis-fast-reroute:
 120
 121 ISIS Fast-Reroute
 122 =================
 123
 124 Unless stated otherwise, commands in this section apply to all LFA
 125 flavors (local LFA, Remote LFA and TI-LFA).
 126
 127 .. clicmd:: spf prefix-priority [critical | high | medium] WORD
 128
 129    Assign a priority to the prefixes that match the specified access-list.
 130
 131    By default loopback prefixes have medium priority and non-loopback prefixes
 132    have low priority.
 133
 134 .. clicmd:: fast-reroute priority-limit [critical | high | medium] [level-1 | level-2]
 135
 136    Limit LFA backup computation up to the specified prefix priority.
 137
 138 .. clicmd:: fast-reroute lfa tiebreaker [downstream | lowest-backup-metric | node-protecting] index (1-255) [level-1 | level-2]
 139
 140    Configure a tie-breaker for multiple local LFA backups. Lower indexes are
 141    processed first.
 142
 143 .. clicmd:: fast-reroute load-sharing disable [level-1 | level-2]
 144
 145    Disable load sharing across multiple LFA backups.
 146
 147 .. clicmd:: fast-reroute remote-lfa prefix-list [WORD] [level-1 | level-2]
 148
 149    Configure a prefix-list to select eligible PQ nodes for remote LFA
 150    backups (valid for all protected interfaces).
 151
 152 .. _isis-region:
 153
 154 ISIS region
 155 ===========
 156
 157 .. clicmd:: is-type [level-1 | level-1-2 | level-2-only]
 158
 159    Define the ISIS router behavior:
 160
 161    - level-1
 162      Act as a station router only
 163    - level-1-2
 164      Act as both a station router and an area router
 165    - level-2-only
 166      Act as an area router only
 167
 168 .. _isis-interface:
 169
 170 ISIS interface
 171 ==============
 172
 173 .. _ip-router-isis-word:
 174
 175 .. clicmd:: <ip|ipv6> router isis WORD
 176
 177    Activate ISIS adjacency on this interface. Note that the name of ISIS
 178    instance must be the same as the one used to configure the ISIS process (see
 179    command :clicmd:`router isis WORD`). To enable IPv4, issue ``ip router isis
 180    WORD``; to enable IPv6, issue ``ipv6 router isis WORD``.
 181
 182 .. clicmd:: isis circuit-type [level-1 | level-1-2 | level-2]
 183
 184    Configure circuit type for interface:
 185
 186    - level-1
 187      Level-1 only adjacencies are formed
 188    - level-1-2
 189      Level-1-2 adjacencies are formed
 190    - level-2-only
 191      Level-2 only adjacencies are formed
 192
 193 .. clicmd:: isis csnp-interval (1-600) [level-1 | level-2]
 194
 195    Set CSNP interval in seconds globally, for an area (level-1) or a domain
 196    (level-2).
 197
 198 .. clicmd:: isis hello padding
 199
 200    Add padding to IS-IS hello packets.
 201
 202 .. clicmd:: isis hello-interval (1-600) [level-1 | level-2]
 203
 204    Set Hello interval in seconds globally, for an area (level-1) or a domain
 205    (level-2).
 206
 207 .. clicmd:: isis hello-multiplier (2-100) [level-1 | level-2]
 208
 209    Set multiplier for Hello holding time globally, for an area (level-1) or a
 210    domain (level-2).
 211
 212 .. clicmd:: isis metric [(0-255) | (0-16777215)] [level-1 | level-2]
 213
 214    Set default metric value globally, for an area (level-1) or a domain
 215    (level-2).  Max value depend if metric support narrow or wide value (see
 216    command :clicmd:`metric-style [narrow | transition | wide]`).
 217
 218 .. clicmd:: isis network point-to-point
 219
 220    Set network type to 'Point-to-Point' (broadcast by default).
 221
 222 .. clicmd:: isis passive
 223
 224    Configure the passive mode for this interface.
 225
 226 .. clicmd:: isis password [clear | md5] <password>
 227
 228    Configure the authentication password (clear or encoded text) for the
 229    interface.
 230
 231 .. clicmd:: isis priority (0-127) [level-1 | level-2]
 232
 233    Set priority for Designated Router election, globally, for the area
 234    (level-1) or the domain (level-2).
 235
 236 .. clicmd:: isis psnp-interval (1-120) [level-1 | level-2]
 237
 238    Set PSNP interval in seconds globally, for an area (level-1) or a domain
 239    (level-2).
 240
 241 .. clicmd:: isis three-way-handshake
 242
 243    Enable or disable :rfc:`5303` Three-Way Handshake for P2P adjacencies.
 244    Three-Way Handshake is enabled by default.
 245
 246 .. clicmd:: isis fast-reroute lfa [level-1 | level-2]
 247
 248    Enable per-prefix local LFA fast reroute link protection.
 249
 250 .. clicmd:: isis fast-reroute lfa [level-1 | level-2] exclude interface IFNAME
 251
 252    Exclude an interface from the local LFA backup nexthop computation.
 253
 254 .. clicmd:: isis fast-reroute remote-lfa tunnel mpls-ldp [level-1 | level-2]
 255
 256    Enable per-prefix Remote LFA fast reroute link protection. Note that other
 257    routers in the network need to be configured to accept LDP targeted hello
 258    messages in order for RLFA to work.
 259
 260 .. clicmd:: isis fast-reroute remote-lfa maximum-metric (1-16777215) [level-1 | level-2]
 261
 262    Limit Remote LFA PQ node selection within the specified metric.
 263
 264 .. clicmd:: isis fast-reroute ti-lfa [level-1|level-2] [node-protection [link-fallback]]
 265
 266    Enable per-prefix TI-LFA fast reroute link or node protection.
 267    When node protection is used, option link-fallback enables the computation and use of
 268    link-protecting LFAs for destinations unprotected by node protection.
 269
 270 .. _showing-isis-information:
 271
 272 Showing ISIS information
 273 ========================
 274
 275 .. clicmd:: show isis summary
 276
 277    Show summary information about ISIS.
 278
 279 .. clicmd:: show isis hostname
 280
 281    Show information about ISIS node.
 282
 283 .. clicmd:: show isis interface [detail] [IFNAME]
 284
 285    Show state and configuration of ISIS specified interface, or all interfaces
 286    if no interface is given with or without details.
 287
 288 .. clicmd:: show isis neighbor [detail] [SYSTEMID]
 289
 290    Show state and information of ISIS specified neighbor, or all neighbors if
 291    no system id is given with or without details.
 292
 293 .. clicmd:: show isis database [detail] [LSPID]
 294
 295    Show the ISIS database globally, for a specific LSP id without or with
 296    details.
 297
 298 .. clicmd:: show isis topology [level-1|level-2]
 299
 300    Show topology IS-IS paths to Intermediate Systems, globally, in area
 301    (level-1) or domain (level-2).
 302
 303 .. clicmd:: show isis route [level-1|level-2] [prefix-sid|backup]
 304
 305    Show the ISIS routing table, as determined by the most recent SPF
 306    calculation.
 307
 308 .. clicmd:: show isis fast-reroute summary [level-1|level-2]
 309
 310    Show information about the number of prefixes having LFA protection,
 311    and network-wide LFA coverage.
 312
 313
 314 .. _isis-traffic-engineering:
 315
 316 Traffic Engineering
 317 ===================
 318
 319 .. note::
 320
 321    At this time, FRR offers partial support for some of the routing protocol
 322    extensions that can be used with MPLS-TE. FRR does not currently support a
 323    complete RSVP-TE solution.
 324
 325 .. clicmd:: mpls-te on
 326
 327    Enable Traffic Engineering LSP flooding.
 328
 329 .. clicmd:: mpls-te router-address <A.B.C.D>
 330
 331    Configure stable IP address for MPLS-TE.
 332
 333 .. clicmd:: show isis mpls-te interface
 334
 335 .. clicmd:: show isis mpls-te interface INTERFACE
 336
 337    Show MPLS Traffic Engineering parameters for all or specified interface.
 338
 339 .. clicmd:: show isis mpls-te router
 340
 341    Show Traffic Engineering router parameters.
 342
 343 .. seealso::
 344
 345    :ref:`ospf-traffic-engineering`
 346
 347
 348 .. _debugging-isis:
 349
 350 Segment Routing
 351 ===============
 352
 353 This is an EXPERIMENTAL support of Segment Routing as per RFC8667
 354 for MPLS dataplane. It supports IPv4, IPv6 and ECMP and has been
 355 tested against Cisco & Juniper routers.
 356
 357 Known limitations:
 358  - No support for level redistribution (L1 to L2 or L2 to L1)
 359  - No support for binding SID
 360  - No support for SRMS
 361  - No support for SRLB
 362  - Only one SRGB and default SPF Algorithm is supported
 363
 364 .. clicmd:: segment-routing on
 365
 366    Enable Segment Routing.
 367
 368 .. clicmd:: segment-routing global-block (16-1048575) (16-1048575) [local-block (16-1048575) (16-1048575)]
 369
 370    Set the Segment Routing Global Block i.e. the label range used by MPLS
 371    to store label in the MPLS FIB for Prefix SID. Note that the block size
 372    may not exceed 65535. Optionally sets also the Segment Routing Local Block.
 373    The negative command always unsets both.
 374
 375 .. clicmd:: segment-routing local-block (16-1048575) (16-1048575)
 376
 377    Set the Segment Routing Local Block i.e. the label range used by MPLS
 378    to store label in the MPLS FIB for Adjacency SID. Note that the block size
 379    may not exceed 65535. This command is deprecated in favor of the combined
 380    'segment-routing global-block A B local-block C D' command.
 381
 382 .. clicmd:: segment-routing node-msd (1-16)
 383
 384    Set the Maximum Stack Depth supported by the router. The value depend of the
 385    MPLS dataplane. E.g. for Linux kernel, since version 4.13 the maximum value
 386    is 32.
 387
 388 .. clicmd:: segment-routing prefix <A.B.C.D/M|X:X::X:X/M> <absolute (16-1048575)|index (0-65535) [no-php-flag|explicit-null] [n-flag-clear]
 389
 390    prefix. The 'no-php-flag' means NO Penultimate Hop Popping that allows SR
 391    node to request to its neighbor to not pop the label. The 'explicit-null'
 392    flag allows SR node to request to its neighbor to send IP packet with the
 393    EXPLICIT-NULL label. The 'n-flag-clear' option can be used to explicitly
 394    clear the Node flag that is set by default for Prefix-SIDs associated to
 395    loopback addresses. This option is necessary to configure Anycast-SIDs.
 396
 397 .. clicmd:: show isis segment-routing nodes
 398
 399    Show detailed information about all learned Segment Routing Nodes.
 400
 401 Debugging ISIS
 402 ==============
 403
 404 .. clicmd:: debug isis adj-packets
 405
 406    IS-IS Adjacency related packets.
 407
 408 .. clicmd:: debug isis checksum-errors
 409
 410    IS-IS LSP checksum errors.
 411
 412 .. clicmd:: debug isis events
 413
 414    IS-IS Events.
 415
 416 .. clicmd:: debug isis local-updates
 417
 418    IS-IS local update packets.
 419
 420 .. clicmd:: debug isis packet-dump
 421
 422    IS-IS packet dump.
 423
 424 .. clicmd:: debug isis protocol-errors
 425
 426    IS-IS LSP protocol errors.
 427
 428 .. clicmd:: debug isis route-events
 429
 430    IS-IS Route related events.
 431
 432 .. clicmd:: debug isis snp-packets
 433
 434    IS-IS CSNP/PSNP packets.
 435
 436 .. clicmd:: debug isis spf-events
 437 .. clicmd:: debug isis spf-statistics
 438 .. clicmd:: debug isis spf-triggers
 439
 440    IS-IS Shortest Path First Events, Timing and Statistic Data and triggering
 441    events.
 442
 443 .. clicmd:: debug isis update-packets
 444
 445
 446    Update related packets.
 447
 448 .. clicmd:: debug isis sr-events
 449
 450
 451    IS-IS Segment Routing events.
 452
 453 .. clicmd:: debug isis lfa
 454
 455
 456    IS-IS LFA events.
 457
 458 .. clicmd:: show debugging isis
 459
 460    Print which ISIS debug level is activate.
 461
 462 .. _isis-config-examples:
 463
 464 ISIS Configuration Examples
 465 ===========================
 466
 467 A simple example, with MD5 authentication enabled:
 468
 469 .. code-block:: frr
 470
 471    !
 472    interface eth0
 473     ip router isis FOO
 474     isis network point-to-point
 475     isis circuit-type level-2-only
 476    !
 477    router isis FOO
 478    net 47.0023.0000.0000.0000.0000.0000.0000.1900.0004.00
 479     metric-style wide
 480     is-type level-2-only
 481
 482
 483 A Traffic Engineering configuration, with Inter-ASv2 support.
 484
 485 First, the :file:`zebra.conf` part:
 486
 487 .. code-block:: frr
 488
 489    hostname HOSTNAME
 490    password PASSWORD
 491    log file /var/log/zebra.log
 492    !
 493    interface eth0
 494     ip address 10.2.2.2/24
 495     link-params
 496      max-bw 1.25e+07
 497      max-rsv-bw 1.25e+06
 498      unrsv-bw 0 1.25e+06
 499      unrsv-bw 1 1.25e+06
 500      unrsv-bw 2 1.25e+06
 501      unrsv-bw 3 1.25e+06
 502      unrsv-bw 4 1.25e+06
 503      unrsv-bw 5 1.25e+06
 504      unrsv-bw 6 1.25e+06
 505      unrsv-bw 7 1.25e+06
 506      admin-grp 0xab
 507    !
 508    interface eth1
 509     ip address 10.1.1.1/24
 510     link-params
 511      enable
 512      metric 100
 513      max-bw 1.25e+07
 514      max-rsv-bw 1.25e+06
 515      unrsv-bw 0 1.25e+06
 516      unrsv-bw 1 1.25e+06
 517      unrsv-bw 2 1.25e+06
 518      unrsv-bw 3 1.25e+06
 519      unrsv-bw 4 1.25e+06
 520      unrsv-bw 5 1.25e+06
 521      unrsv-bw 6 1.25e+06
 522      unrsv-bw 7 1.25e+06
 523      neighbor 10.1.1.2 as 65000
 524
 525
 526 Then the :file:`isisd.conf` itself:
 527
 528 .. code-block:: frr
 529
 530    hostname HOSTNAME
 531    password PASSWORD
 532    log file /var/log/isisd.log
 533    !
 534    !
 535    interface eth0
 536     ip router isis FOO
 537    !
 538    interface eth1
 539     ip router isis FOO
 540    !
 541    !
 542    router isis FOO
 543     isis net 47.0023.0000.0000.0000.0000.0000.0000.1900.0004.00
 544      mpls-te on
 545      mpls-te router-address 10.1.1.1
 546    !
 547    line vty
 548
 549 A Segment Routing configuration, with IPv4, IPv6, SRGB and MSD configuration.
 550
 551 .. code-block:: frr
 552
 553    hostname HOSTNAME
 554    password PASSWORD
 555    log file /var/log/isisd.log
 556    !
 557    !
 558    interface eth0
 559     ip router isis SR
 560     isis network point-to-point
 561    !
 562    interface eth1
 563     ip router isis SR
 564    !
 565    !
 566    router isis SR
 567     net 49.0000.0000.0000.0001.00
 568     is-type level-1
 569     topology ipv6-unicast
 570     lsp-gen-interval 2
 571     segment-routing on
 572     segment-routing node-msd 8
 573     segment-routing prefix 10.1.1.1/32 index 100 explicit-null
 574     segment-routing prefix 2001:db8:1000::1/128 index 101 explicit-null
 575    !
 576
 577
 578 .. _isis-vrf-config-examples:
 579
 580 ISIS Vrf Configuration Examples
 581 ===============================
 582
 583 A simple vrf example:
 584
 585 .. code-block:: frr
 586
 587    !
 588    interface eth0 vrf RED
 589     ip router isis FOO vrf RED
 590     isis network point-to-point
 591     isis circuit-type level-2-only
 592    !
 593    router isis FOO vrf RED
 594     net 47.0023.0000.0000.0000.0000.0000.0000.1900.0004.00
 595     metric-style wide
 596     is-type level-2-only