doc/user/pim.rst

   1 .. _pim:
   2
   3 ***
   4 PIM
   5 ***
   6
   7 PIM -- Protocol Independent Multicast
   8
   9 *pimd* supports pim-sm as well as igmp v2 and v3. pim is
  10 vrf aware and can work within the context of vrf's in order to
  11 do S,G mrouting.  Additionally PIM can be used in the EVPN underlay
  12 network for optimizing forwarding of overlay BUM traffic.
  13
  14 .. note::
  15
  16    On Linux for PIM-SM operation you *must* have kernel version 4.18 or greater.
  17    To use PIM for EVPN BUM forwarding, kernels 5.0 or greater are required.
  18    OpenBSD has no multicast support and FreeBSD, NetBSD and Solaris only
  19    have support for SSM.
  20
  21 .. _starting-and-stopping-pimd:
  22
  23 Starting and Stopping pimd
  24 ==========================
  25
  26 The default configuration file name of *pimd*'s is :file:`pimd.conf`. When
  27 invoked *pimd* searches directory |INSTALL_PREFIX_ETC|. If
  28 :file:`pimd.conf` is not there then next search current directory.
  29
  30 *pimd* requires zebra for proper operation. Additionally *pimd* depends on
  31 routing properly setup and working in the network that it is working on.
  32
  33 ::
  34
  35    # zebra -d
  36    # pimd -d
  37
  38
  39 Please note that *zebra* must be invoked before *pimd*.
  40
  41 To stop *pimd* please use::
  42
  43    kill `cat /var/run/pimd.pid`
  44
  45 Certain signals have special meanings to *pimd*.
  46
  47 +---------+---------------------------------------------------------------------+
  48 | Signal  | Meaning                                                             |
  49 +=========+=====================================================================+
  50 | SIGUSR1 | Rotate the *pimd* logfile                                           |
  51 +---------+---------------------------------------------------------------------+
  52 | SIGINT  | *pimd* sweeps all installed PIM mroutes then terminates gracefully. |
  53 | SIGTERM |                                                                     |
  54 +---------+---------------------------------------------------------------------+
  55
  56 *pimd* invocation options. Common options that can be specified
  57 (:ref:`common-invocation-options`).
  58
  59 .. index:: ip pim rp A.B.C.D A.B.C.D/M
  60 .. clicmd:: ip pim rp A.B.C.D A.B.C.D/M
  61
  62    In order to use pim, it is necessary to configure a RP for join messages to
  63    be sent to. Currently the only methodology to do this is via static rp
  64    commands. All routers in the pim network must agree on these values. The
  65    first ip address is the RP's address and the second value is the matching
  66    prefix of group ranges covered. This command is vrf aware, to configure for
  67    a vrf, enter the vrf submode.
  68
  69 .. index:: ip pim register-accept-list PLIST
  70 .. clicmd:: ip pim register-accept-list PLIST
  71
  72    When pim receives a register packet the source of the packet will be compared
  73    to the prefix-list specified, PLIST, and if a permit is received normal
  74    processing continues.  If a deny is returned for the source address of the
  75    register packet a register stop message is sent to the source.
  76
  77 .. index:: ip pim spt-switchover infinity-and-beyond
  78 .. clicmd:: ip pim spt-switchover infinity-and-beyond
  79
  80    On the last hop router if it is desired to not switch over to the SPT tree.
  81    Configure this command. This command is vrf aware, to configure for a vrf,
  82    enter the vrf submode.
  83
  84 .. index:: ip pim ecmp
  85 .. clicmd:: ip pim ecmp
  86
  87    If pim has the a choice of ECMP nexthops for a particular RPF, pim will
  88    cause S,G flows to be spread out amongst the nexthops. If this command is
  89    not specified then the first nexthop found will be used. This command is vrf
  90    aware, to configure for a vrf, enter the vrf submode.
  91
  92 .. index:: ip pim ecmp rebalance
  93 .. clicmd:: ip pim ecmp rebalance
  94
  95    If pim is using ECMP and an interface goes down, cause pim to rebalance all
  96    S,G flows across the remaining nexthops. If this command is not configured
  97    pim only modifies those S,G flows that were using the interface that went
  98    down. This command is vrf aware, to configure for a vrf, enter the vrf
  99    submode.
 100
 101 .. index:: ip pim join-prune-interval (60-600)
 102 .. clicmd:: ip pim join-prune-interval (60-600)
 103
 104    Modify the join/prune interval that pim uses to the new value. Time is
 105    specified in seconds. This command is vrf aware, to configure for a vrf,
 106    enter the vrf submode.
 107
 108 .. index:: ip pim keep-alive-timer (31-60000)
 109 .. clicmd:: ip pim keep-alive-timer (31-60000)
 110
 111    Modify the time out value for a S,G flow from 31-60000 seconds. 31 seconds
 112    is chosen for a lower bound because some hardware platforms cannot see data
 113    flowing in better than 30 second chunks. This command is vrf aware, to
 114    configure for a vrf, enter the vrf submode.
 115
 116 .. index:: ip pim packets (1-100)
 117 .. clicmd:: ip pim packets (1-100)
 118
 119    When processing packets from a neighbor process the number of packets
 120    incoming at one time before moving on to the next task. The default value is
 121    3 packets.  This command is only useful at scale when you can possibly have
 122    a large number of pim control packets flowing. This command is vrf aware, to
 123    configure for a vrf, enter the vrf submode.
 124
 125 .. index:: ip pim register-suppress-time (5-60000)
 126 .. clicmd:: ip pim register-suppress-time (5-60000)
 127
 128    Modify the time that pim will register suppress a FHR will send register
 129    notifications to the kernel. This command is vrf aware, to configure for a
 130    vrf, enter the vrf submode.
 131
 132 .. index:: ip pim send-v6-secondary
 133 .. clicmd:: ip pim send-v6-secondary
 134
 135    When sending pim hello packets tell pim to send any v6 secondary addresses
 136    on the interface. This information is used to allow pim to use v6 nexthops
 137    in it's decision for RPF lookup. This command is vrf aware, to configure for
 138    a vrf, enter the vrf submode.
 139
 140 .. index:: ip pim ssm prefix-list WORD
 141 .. clicmd:: ip pim ssm prefix-list WORD
 142
 143    Specify a range of group addresses via a prefix-list that forces pim to
 144    never do SM over. This command is vrf aware, to configure for a vrf, enter
 145    the vrf submode.
 146
 147 .. index:: ip multicast rpf-lookup-mode WORD
 148 .. clicmd:: ip multicast rpf-lookup-mode WORD
 149
 150    Modify how PIM does RPF lookups in the zebra routing table.  You can use
 151    these choices:
 152
 153    longer-prefix
 154       Lookup the RPF in both tables using the longer prefix as a match
 155
 156    lower-distance
 157       Lookup the RPF in both tables using the lower distance as a match
 158
 159    mrib-only
 160       Lookup in the Multicast RIB only
 161
 162    mrib-then-urib
 163       Lookup in the Multicast RIB then the Unicast Rib, returning first found.
 164       This is the default value for lookup if this command is not entered
 165
 166    urib-only
 167       Lookup in the Unicast Rib only.
 168
 169 .. index:: [no] ip msdp mesh-group [WORD]
 170 .. clicmd:: [no] ip msdp mesh-group [WORD]
 171
 172    Create or Delete a multicast source discovery protocol mesh-group using
 173    [WORD] as the group name.
 174
 175 .. index:: [no] ip msdp mesh-group WORD member A.B.C.D
 176 .. clicmd:: [no] ip msdp mesh-group WORD member A.B.C.D
 177
 178    Attach or Delete A.B.C.D to the MSDP mesh group WORD specified.
 179
 180 .. index:: [no] ip msdp mesh-group WORD source A.B.C.D
 181 .. clicmd:: [no] ip msdp mesh-group WORD source A.B.C.D
 182
 183    For the address specified A.B.C.D use that as the source address for
 184    mesh group packets being sent.
 185
 186 .. index:: ip igmp generate-query-once [version (2-3)]
 187 .. clicmd:: ip igmp generate-query-once [version (2-3)]
 188
 189    Generate IGMP query (v2/v3) on user requirement. This will not depend on
 190    the existing IGMP general query timer.If no version is provided in the cli,
 191    it will be considered as default v2 query.This is a hidden command.
 192
 193 .. index:: [no] ip igmp watermark-warn (10-60000)
 194 .. clicmd:: [no] ip igmp watermark-warn (10-60000)
 195
 196    Configure watermark warning generation for an igmp group limit. Generates
 197    warning once the configured group limit is reached while adding new groups.
 198    'no' form of the command disables the warning generation. This command is
 199    vrf aware. To configure per vrf, enter vrf submode.
 200
 201 .. _pim-interface-configuration:
 202
 203 PIM Interface Configuration
 204 ===========================
 205
 206 PIM interface commands allow you to configure an interface as either a Receiver
 207 or a interface that you would like to form pim neighbors on. If the interface
 208 is in a vrf, enter the interface command with the vrf keyword at the end.
 209
 210 .. index:: ip pim active-active
 211 .. clicmd:: ip pim active-active
 212
 213    Turn on pim active-active configuration for a Vxlan interface.  This
 214    command will not do anything if you do not have the underlying ability
 215    of a mlag implementation.
 216
 217 .. index:: ip pim bfd
 218 .. clicmd:: ip pim bfd
 219
 220    Turns on BFD support for PIM for this interface.
 221
 222 .. index:: ip pim bsm
 223 .. clicmd:: ip pim bsm
 224
 225    Tell pim that we would like to use this interface to process bootstrap
 226    messages. This is enabled by default. 'no' form of this command is used to
 227    restrict bsm messages on this interface.
 228
 229 .. index:: ip pim unicast-bsm
 230 .. clicmd:: ip pim unicast-bsm
 231
 232    Tell pim that we would like to allow interface to process unicast bootstrap
 233    messages. This is enabled by default. 'no' form of this command is used to
 234    restrict processing of unicast bsm messages on this interface.
 235
 236 .. index:: ip pim drpriority (1-4294967295)
 237 .. clicmd:: ip pim drpriority (1-4294967295)
 238
 239    Set the DR Priority for the interface. This command is useful to allow the
 240    user to influence what node becomes the DR for a lan segment.
 241
 242 .. index:: ip pim hello (1-180) (1-180)
 243 .. clicmd:: ip pim hello (1-180) (1-180)
 244
 245    Set the pim hello and hold interval for a interface.
 246
 247 .. index:: ip pim
 248 .. clicmd:: ip pim
 249
 250    Tell pim that we would like to use this interface to form pim neighbors
 251    over. Please note that this command does not enable the reception of IGMP
 252    reports on the interface. Refer to the next `ip igmp` command for IGMP
 253    management.
 254
 255 .. index:: ip igmp
 256 .. clicmd:: ip igmp
 257
 258    Tell pim to receive IGMP reports and Query on this interface. The default
 259    version is v3. This command is useful on a LHR.
 260
 261 .. index:: ip igmp join A.B.C.D [A.B.C.D]
 262 .. clicmd:: ip igmp join A.B.C.D [A.B.C.D]
 263
 264    Join multicast group or source-group on an interface.
 265
 266 .. index:: ip igmp query-interval (1-1800)
 267 .. clicmd:: ip igmp query-interval (1-1800)
 268
 269    Set the IGMP query interval that PIM will use.
 270
 271 .. index:: ip igmp query-max-response-time (10-250)
 272 .. clicmd:: ip igmp query-max-response-time (10-250)
 273
 274    Set the IGMP query response timeout value. If an report is not returned in
 275    the specified time we will assume the S,G or \*,G has timed out.
 276
 277 .. index:: ip igmp version (2-3)
 278 .. clicmd:: ip igmp version (2-3)
 279
 280    Set the IGMP version used on this interface. The default value is 3.
 281
 282 .. index:: ip multicast boundary oil WORD
 283 .. clicmd:: ip multicast boundary oil WORD
 284
 285    Set a pim multicast boundary, based upon the WORD prefix-list. If a pim join
 286    or IGMP report is received on this interface and the Group is denied by the
 287    prefix-list, PIM will ignore the join or report.
 288
 289 .. index:: ip igmp last-member-query-count (1-7)
 290 .. clicmd:: ip igmp last-member-query-count (1-7)
 291
 292    Set the IGMP last member query count. The default value is 2. 'no' form of
 293    this command is used to to configure back to the default value.
 294
 295 .. index:: ip igmp last-member-query-interval (1-255)
 296 .. clicmd:: ip igmp last-member-query-interval (1-255)
 297
 298    Set the IGMP last member query interval in deciseconds. The default value is
 299    10 deciseconds. 'no' form of this command is used to to configure back to the
 300    default value.
 301
 302 .. index:: ip mroute INTERFACE A.B.C.D [A.B.C.D]
 303 .. clicmd:: ip mroute INTERFACE A.B.C.D [A.B.C.D]
 304
 305    Set a static multicast route for a traffic coming on the current interface to
 306    be forwarded on the given interface if the traffic matches the group address
 307    and optionally the source address.
 308
 309 .. _pim-multicast-rib-insertion:
 310
 311 PIM Multicast RIB insertion:
 312 ============================
 313
 314 In order to influence Multicast RPF lookup, it is possible to insert
 315 into zebra routes for the Multicast RIB. These routes are only
 316 used for RPF lookup and will not be used by zebra for insertion
 317 into the kernel *or* for normal rib processing. As such it is
 318 possible to create weird states with these commands. Use with
 319 caution. Most of the time this will not be necessary.
 320
 321 .. index:: ip mroute A.B.C.D/M A.B.C.D (1-255)
 322 .. clicmd:: ip mroute A.B.C.D/M A.B.C.D (1-255)
 323
 324    Insert into the Multicast Rib Route A.B.C.D/M with specified nexthop. The
 325    distance can be specified as well if desired.
 326
 327 .. index:: ip mroute A.B.C.D/M INTERFACE (1-255)
 328 .. clicmd:: ip mroute A.B.C.D/M INTERFACE (1-255)
 329
 330    Insert into the Multicast Rib Route A.B.C.D/M using the specified INTERFACE.
 331    The distance can be specified as well if desired.
 332
 333 .. _show-pim-information:
 334
 335 Show PIM Information
 336 ====================
 337
 338 All PIM show commands are vrf aware and typically allow you to insert a
 339 specified vrf command if information is desired about a specific vrf. If no
 340 vrf is specified then the default vrf is assumed. Finally the special keyword
 341 'all' allows you to look at all vrfs for the command. Naming a vrf 'all' will
 342 cause great confusion.
 343
 344 .. index:: show ip igmp interface
 345 .. clicmd:: show ip igmp interface
 346
 347    Display IGMP interface information.
 348
 349 .. index:: show ip igmp join
 350 .. clicmd:: show ip igmp join
 351
 352    Display IGMP static join information.
 353
 354 .. index:: show ip igmp groups
 355 .. clicmd:: show ip igmp groups
 356
 357    Display IGMP groups information.
 358
 359 .. index:: show ip igmp groups retransmissions
 360 .. clicmd:: show ip igmp groups retransmissions
 361
 362    Display IGMP group retransmission information.
 363
 364 .. index:: show ip igmp sources
 365 .. clicmd:: show ip igmp sources
 366
 367    Display IGMP sources information.
 368
 369 .. index:: show ip igmp sources retransmissions
 370 .. clicmd:: show ip igmp sources retransmissions
 371
 372    Display IGMP source retransmission information.
 373
 374 .. index:: show ip igmp statistics
 375 .. clicmd:: show ip igmp statistics
 376
 377    Display IGMP statistics information.
 378
 379 .. index:: show ip multicast
 380 .. clicmd:: show ip multicast
 381
 382    Display various information about the interfaces used in this pim instance.
 383
 384 .. index:: show ip mroute [vrf NAME] [A.B.C.D [A.B.C.D]] [fill] [json]
 385 .. clicmd:: show ip mroute [vrf NAME] [A.B.C.D [A.B.C.D]] [fill] [json]
 386
 387    Display information about installed into the kernel S,G mroutes.  If
 388    one address is specified we assume it is the Group we are interested
 389    in displaying data on.  If the second address is specified then it is
 390    Source Group.  The keyword `fill` says to fill in all assumed data
 391    for test/data gathering purposes.
 392
 393 .. index:: show ip mroute [vrf NAME] count [json]
 394 .. clicmd:: show ip mroute [vrf NAME] count [json]
 395
 396    Display information about installed into the kernel S,G mroutes and in
 397    addition display data about packet flow for the mroutes for a specific
 398    vrf.
 399
 400 .. index:: show ip mroute vrf all count [json]
 401 .. clicmd:: show ip mroute vrf all count [json]
 402
 403    Display information about installed into the kernel S,G mroutes and in
 404    addition display data about packet flow for the mroutes for all vrfs.
 405
 406 .. index:: show ip mroute [vrf NAME] summary [json]
 407 .. clicmd:: show ip mroute [vrf NAME] summary [json]
 408
 409    Display total number of S,G mroutes and number of S,G mroutes installed
 410    into the kernel for a specific vrf.
 411
 412 .. index:: show ip mroute vrf all summary [json]
 413 .. clicmd:: show ip mroute vrf all summary [json]
 414
 415    Display total number of S,G mroutes and number of S,G mroutes
 416    installed into the kernel for all vrfs.
 417
 418 .. index:: show ip pim assert
 419 .. clicmd:: show ip pim assert
 420
 421    Display information about asserts in the PIM system for S,G mroutes.
 422
 423 .. index:: show ip pim assert-internal
 424 .. clicmd:: show ip pim assert-internal
 425
 426    Display internal assert state for S,G mroutes
 427
 428 .. index:: show ip pim assert-metric
 429 .. clicmd:: show ip pim assert-metric
 430
 431    Display metric information about assert state for S,G mroutes
 432
 433 .. index:: show ip pim assert-winner-metric
 434 .. clicmd:: show ip pim assert-winner-metric
 435
 436    Display winner metric for assert state for S,G mroutes
 437
 438 .. index:: show ip pim group-type
 439 .. clicmd:: show ip pim group-type
 440
 441    Display SSM group ranges.
 442
 443 .. index:: show ip pim interface
 444 .. clicmd:: show ip pim interface
 445
 446    Display information about interfaces PIM is using.
 447
 448 .. index:: show ip pim mlag [vrf NAME] interface [detail|WORD] [json]
 449 .. clicmd:: show ip pim mlag [vrf NAME|all] interface [detail|WORD] [json]
 450
 451    Display mlag interface information.
 452
 453 .. index:: show ip pim [vrf NAME] join [A.B.C.D [A.B.C.D]] [json]
 454 .. clicmd:: show ip pim join
 455
 456    Display information about PIM joins received.  If one address is specified
 457    then we assume it is the Group we are interested in displaying data on.
 458    If the second address is specified then it is Source Group.
 459
 460 .. index:: show ip pim local-membership
 461 .. clicmd:: show ip pim local-membership
 462
 463    Display information about PIM interface local-membership.
 464
 465 .. index:: show ip pim mlag summary [json]
 466 .. clicmd:: show ip pim mlag summary [json]
 467
 468    Display mlag information state that PIM is keeping track of.
 469
 470 .. index:: show ip pim neighbor
 471 .. clicmd:: show ip pim neighbor
 472
 473    Display information about PIM neighbors.
 474
 475 .. index:: show ip pim nexthop
 476 .. clicmd:: show ip pim nexthop
 477
 478    Display information about pim nexthops that are being used.
 479
 480 .. index:: show ip pim nexthop-lookup
 481 .. clicmd:: show ip pim nexthop-lookup
 482
 483    Display information about a S,G pair and how the RPF would be chosen. This
 484    is especially useful if there are ECMP's available from the RPF lookup.
 485
 486 .. index:: show ip pim rp-info
 487 .. clicmd:: show ip pim rp-info
 488
 489    Display information about RP's that are configured on this router.
 490
 491 .. index:: show ip pim rpf
 492 .. clicmd:: show ip pim rpf
 493
 494    Display information about currently being used S,G's and their RPF lookup
 495    information. Additionally display some statistics about what has been
 496    happening on the router.
 497
 498 .. index:: show ip pim secondary
 499 .. clicmd:: show ip pim secondary
 500
 501    Display information about an interface and all the secondary addresses
 502    associated with it.
 503
 504 .. index:: show ip pim state
 505 .. clicmd:: show ip pim state
 506
 507    Display information about known S,G's and incoming interface as well as the
 508    OIL and how they were chosen.
 509
 510 .. index:: show ip pim [vrf NAME] upstream [A.B.C.D [A.B.C.D]] [json]
 511 .. clicmd:: show ip pim upstream
 512
 513    Display upstream information about a S,G mroute.  Allow the user to
 514    specify sub Source and Groups that we are only interested in.
 515
 516 .. index:: show ip pim upstream-join-desired
 517 .. clicmd:: show ip pim upstream-join-desired
 518
 519    Display upstream information for S,G's and if we desire to
 520    join the multicast tree
 521
 522 .. index:: show ip pim upstream-rpf
 523 .. clicmd:: show ip pim upstream-rpf
 524
 525    Display upstream information for S,G's and the RPF data associated with them.
 526
 527 .. index:: show ip pim [vrf NAME] mlag upstream [A.B.C.D [A.B.C.D]] [json]
 528 .. clicmd:: show ip pim mlag upstream
 529
 530    Display upstream entries that are synced across MLAG switches.
 531    Allow the user to specify sub Source and Groups address filters.
 532
 533 .. index:: show ip pim mlag summary
 534 .. clicmd:: show ip pim mlag summary
 535
 536    Display PIM MLAG (multi-chassis link aggregation) session status and
 537    control message statistics.
 538
 539 .. index:: show ip pim bsr
 540 .. clicmd:: show ip pim bsr
 541
 542    Display current bsr, its uptime and last received bsm age.
 543
 544 .. index:: show ip pim bsrp-info
 545 .. clicmd:: show ip pim bsrp-info
 546
 547    Display group-to-rp mappings received from E-BSR.
 548
 549 .. index:: show ip pim bsm-database
 550 .. clicmd:: show ip pim bsm-database
 551
 552    Display all fragments ofstored bootstrap message in user readable format.
 553
 554 .. index:: show ip rpf
 555 .. clicmd:: show ip rpf
 556
 557    Display the multicast RIB created in zebra.
 558
 559 .. index:: mtrace A.B.C.D [A.B.C.D]
 560 .. clicmd:: mtrace A.B.C.D [A.B.C.D]
 561
 562    Display multicast traceroute towards source, optionally for particular group.
 563
 564 .. index:: show ip multicast count [vrf NAME] [json]
 565 .. clicmd:: show ip multicast count [vrf NAME] [json]
 566
 567    Display multicast data packets count per interface for a vrf.
 568
 569 .. index:: show ip multicast count vrf all [json]
 570 .. clicmd:: show ip multicast count vrf all [json]
 571
 572    Display multicast data packets count per interface for all vrf.
 573
 574 PIM Debug Commands
 575 ==================
 576
 577 The debugging subsystem for PIM behaves in accordance with how FRR handles
 578 debugging. You can specify debugging at the enable CLI mode as well as the
 579 configure CLI mode. If you specify debug commands in the configuration cli
 580 mode, the debug commands can be persistent across restarts of the FRR pimd if
 581 the config was written out.
 582
 583 .. index:: debug igmp
 584 .. clicmd:: debug igmp
 585
 586    This turns on debugging for IGMP protocol activity.
 587
 588 .. index:: debug mtrace
 589 .. clicmd:: debug mtrace
 590
 591    This turns on debugging for mtrace protocol activity.
 592
 593 .. index:: debug mroute
 594 .. clicmd:: debug mroute
 595
 596    This turns on debugging for PIM interaction with kernel MFC cache.
 597
 598 .. index:: debug pim events
 599 .. clicmd:: debug pim events
 600
 601    This turns on debugging for PIM system events. Especially timers.
 602
 603 .. index:: debug pim nht
 604 .. clicmd:: debug pim nht
 605
 606    This turns on debugging for PIM nexthop tracking. It will display
 607    information about RPF lookups and information about when a nexthop changes.
 608
 609 .. index:: debug pim packet-dump
 610 .. clicmd:: debug pim packet-dump
 611
 612    This turns on an extraordinary amount of data. Each pim packet sent and
 613    received is dumped for debugging purposes. This should be considered a
 614    developer only command.
 615
 616 .. index:: debug pim packets
 617 .. clicmd:: debug pim packets
 618
 619    This turns on information about packet generation for sending and about
 620    packet handling from a received packet.
 621
 622 .. index:: debug pim trace
 623 .. clicmd:: debug pim trace
 624
 625    This traces pim code and how it is running.
 626
 627 .. index:: debug pim bsm
 628 .. clicmd:: debug pim bsm
 629
 630    This turns on debugging for BSR message processing.
 631
 632 .. index:: debug pim zebra
 633 .. clicmd:: debug pim zebra
 634
 635    This gathers data about events from zebra that come up through the ZAPI.
 636
 637 PIM Clear Commands
 638 ==================
 639 Clear commands reset various variables.
 640
 641 .. index:: clear ip interfaces
 642 .. clicmd:: clear ip interfaces
 643
 644    Reset interfaces.
 645
 646 .. index:: clear ip igmp interfaces
 647 .. clicmd:: clear ip igmp interfaces
 648
 649    Reset IGMP interfaces.
 650
 651 .. index:: clear ip mroute
 652 .. clicmd:: clear ip mroute
 653
 654    Reset multicast routes.
 655
 656 .. index:: clear ip mroute [vrf NAME] count
 657 .. clicmd:: clear ip mroute [vrf NAME] count
 658
 659    When this command is issued, reset the counts of data shown for
 660    packet count, byte count and wrong interface to 0 and start count
 661    up from this spot.
 662
 663 .. index:: clear ip pim interfaces
 664 .. clicmd:: clear ip pim interfaces
 665
 666    Reset PIM interfaces.
 667
 668 .. index:: clear ip pim oil
 669 .. clicmd:: clear ip pim oil
 670
 671    Rescan PIM OIL (output interface list).
 672
 673 PIM EVPN configuration
 674 ======================
 675 To use PIM in the underlay for overlay BUM forwarding associate a multicast
 676 group with the L2 VNI. The actual configuration is based on your distribution.
 677 Here is an ifupdown2 example::
 678
 679    auto vx-10100
 680    iface vx-10100
 681        vxlan-id 10100
 682        bridge-access 100
 683        vxlan-local-tunnelip 27.0.0.11
 684        vxlan-mcastgrp 239.1.1.100
 685
 686 .. note::
 687
 688    PIM will see the ``vxlan-mcastgrp`` configuration and auto configure state
 689    to properly forward BUM traffic.
 690
 691 PIM also needs to be configured in the underlay to allow the BUM MDT to be
 692 setup. This is existing PIM configuration:
 693
 694 - Enable pim on the underlay L3 interface via the "ip pim" command.
 695 - Configure RPs for the BUM multicast group range.
 696 - Ensure the PIM is enabled on the lo of the VTEPs and the RP.