# PIM

PIM -- Protocol Independent Multicast

pimd supports PIM-SM as well as IGMP v2 and v3. PIM is VRF-aware and can work within the context of VRFs in order to do S,G mrouting. Additionally, PIM can be used in the EVPN underlay network for optimizing forwarding of overlay BUM traffic.

Note

On Linux, kernel version 4.19 or greater is recommended for PIM-SM (ASM). Kernels from 4.19 onward deliver the `IGMPMSG_WRVIFWHOLE` upcall, which carries the ingress interface and the full packet. That path drives first-hop router (FHR) activation and PIM register encapsulation of the first data packet to the RP.

On Linux kernels older than 4.19 (for example some RHEL/Rocky 8 systems), only `IGMPMSG_WRONGVIF` is available. pimd detects this at runtime and compensates via the WRONGVIF handler for several cases (join-before-data, source and receiver on the same LAN, LHR / SPT switch, and `(S,G)` MFC recovery after pimd restart). This support is best-effort: WRONGVIF does not include the packet buffer, so register encapsulation of the first data packet still requires `IGMPMSG_WRVIFWHOLE` (kernel >= 4.19). On kernels that deliver WRVIFWHOLE, compensation is not used after the first such upcall.

To use PIM for EVPN BUM forwarding, kernels 5.0 or greater are required. OpenBSD has no multicast support and FreeBSD, and NetBSD only have support for SSM.

## Starting and Stopping pimd

Configuration for the daemon should be saved in the FRR integrated configuration file located in /etc/frr/frr.conf, see Integrated Config File for more information on system configuration.

Prior versions of FRR supported reading and writing per-daemon config files; however, with the introduction of the centralized management daemon `mgmtd` this could no longer be supported.

In order to allow for an orderly transition from per-daemon config files to the integrated config file, FRR daemons will continue to try and read their specific per-daemon configuration file as before. Additionally the config can still be loaded directly using the `-f` or `--config-file` CLI options; however, these files will not be updated when the configuration is written (e.g., with the `write mem` command).

Warning

Per-daemon files will no longer be updated when the user issues a `write memory` command. Therefore these per-daemon config files should only be used as a mechanism for transitioning to the integrated config, and then removed.

If starting daemons by hand then please note, pimd requires zebra for proper operation. Additionally pimd depends on routing properly setup and working in the network that it is working on.

    # zebra -d
    # pimd -d

Please note that zebra must be invoked before pimd.

To stop pimd please use:

    kill `cat /var/run/frr/pimd.pid`

Certain signals have special meanings to pimd.

Signal | Meaning
--- | ---
SIGUSR1 | Rotate the pimd logfile
SIGINT SIGTERM | pimd sweeps all installed PIM mroutes then terminates gracefully.

pimd invocation options. Common options that can be specified (Common Invocation Options).

### PIM Routers

router pim [vrf NAME]

  Configure the global PIM protocol. To configure the PIM instance for a VRF, specify the VRF name. In contrast to other protocols, this does not enable PIM operation but merely serves as a container for per-instance configuration parameters. Likewise, the `no` form does not disable PIM.

rp A.B.C.D A.B.C.D/M

  In order to use PIM, it is necessary to configure an RP for join messages to be sent to. This command statically configures an RP. All routers in the PIM network must agree on these values. The first IP address is the RP's address and the second value is the matching prefix of group ranges covered. This command is VRF-aware.

no autorp discovery

  In order to use PIM, it is necessary to configure an RP for join messages to be sent to. FRR supports learning RP information dynamically via the AutoRP protocol and performs discovery by default. This command will disable the AutoRP discovery protocol. Any RP information previously learned via AutoRP is removed immediately from the running configuration. All routers in the PIM network must agree on the network RP information, so all routers in the network should have AutoRP either enabled or disabled. Use `autorp discovery` to re-enable AutoRP discovery. This command is VRF-aware.

autorp announce A.B.C.D [A.B.C.D/M | group-list PREFIX_LIST]

  Configure the router to advertise itself as a candidate PIM-SM RP via AutoRP. The supported groups can be defined as a single group range, or multiple group ranges can be defined via a prefix list.

autorp announce {scope (1-255) | interval (1-65535) | holdtime (0-65535)}

  Configure the AutoRP advertise messages. The scope defines the TTL value in the messages to limit the scope, defaults to 31. Interval defines the number of seconds elapsed between advertise messages sent, defaults to 60. Hold time defines how long the AutoRP mapping agent will consider the information valid, setting to 0 will disable expiration of the candidate RP information, defaults to 3 * interval.

autorp send-rp-discovery [source <address A.B.C.D | interface IFNAME | loopback | any>]

  Enable the AutoRP mapping agent on this router. The mapping agent listens for candidate RP announcements, aggregates them, and sends AutoRP discovery messages so other routers can learn RP information dynamically. By default the source address is the highest loopback address. Use `interface` to select the highest address on an interface, `address` to set an explicit address, or `any` to use the highest address on any interface. Use `no autorp send-rp-discovery` to disable the mapping agent. This command is VRF-aware.

autorp send-rp-discovery {scope (0-255) | interval (1-65535) | holdtime (0-65535)}

  Configure AutoRP mapping agent discovery messages. The scope defines the TTL value in the messages to limit the scope, defaults to 31. Interval defines the number of seconds elapsed between discovery messages sent, defaults to 60. Hold time defines how long other routers should consider learned RP information valid, defaults to 180 seconds.

rp keep-alive-timer (1-65535)

  Modify the timeout value for an S,G flow from 1-65535 seconds at RP. The normal keepalive period for the KAT(S,G) defaults to 210 seconds. However, at the RP, the keepalive period must be at least the Register_Suppression_Time, or the RP may time out the (S,G) state before the next Null-Register arrives. Thus, the KAT(S,G) is set to max(Keepalive_Period, RP_Keepalive_Period) when a Register-Stop is sent. If choosing a value below 31 seconds be aware that some hardware platforms cannot see data flowing in better than 30 second chunks. This command is VRF-aware.

bsr candidate-bsr [priority (0-255)] [source [address A.B.C.D] | [interface INTERFACE] | [loopback] | [any]]

  Configure the router to advertise itself as a candidate PIM-SM BSR. The candidate with the highest priority becomes the BSR for the domain (high wins). When priority is the same for more than one candidate BSR, the candidate with the highest IP address becomes the BSR of the domain. The address can be configured explicitly via `address`, or be selecting an interface name using `interface`. If `any` is configured the highest address from any interface will be selected. By default, the highest loopback address is selected, which can also be configured via `loopback`

bsr candidate-rp [interval]

  Configure the router to advertise itself as a candidate PIM-SM RP at the specified `interval` in seconds.

bsr candidate-rp group A.B.C.D/M

  Configure the multicast group prefix that this candidate RP advertises itself for. This command can be repeated for all desired groups that need to be added to the candidate RP advertisement.

bsr candidate-rp [priority (0-255)] [source [address A.B.C.D] | [interface INTERFACE] | [loopback] | [any]]

  Configure the router to advertise itself as a candidate PIM-SM RP. `interval` can be used to configure the interval in seconds to send these advertisements. The candidate with the lowest priority becomes the RP for the domain (low wins). When priority is the same for more than one candidate RP, the candidate with the highest IP address becomes the BSR of the domain. The address can be configured explicitly via `address`, or be selecting an interface name using `interface`. If `any` is configured the highest address from any interface will be selected.By default, the highest loopback address is selected, which can also be configured via `loopback`.

register-accept-list PLIST

  When PIM receives a register packet the source of the packet will be compared to the prefix-list specified, PLIST, and if a permit is received normal processing continues. If a deny is returned for the source address of the register packet a register stop message is sent to the source.

spt-switchover infinity-and-beyond [prefix-list PLIST]

  On the last hop router if it is desired to not switch over to the SPT tree configure this command. Optional parameter prefix-list can be use to control which groups to switch or not switch. If a group is PERMIT as per the PLIST, then the SPT switchover does not happen for it and if it is DENY, then the SPT switchover happens. This command is VRF-aware.

ecmp

  If PIM has the a choice of ECMP nexthops for a particular RPF, PIM will cause S,G flows to be spread out amongst the nexthops. If this command is not specified then the first nexthop found will be used. This command is VRF-aware.

ecmp rebalance

  If PIM is using ECMP and an interface goes down, cause PIM to rebalance all S,G flows across the remaining nexthops. If this command is not configured PIM only modifies those S,G flows that were using the interface that went down. This command is VRF-aware.

join-prune-interval (1-65535)

  Modify the join/prune interval that PIM uses to the new value. Time is specified in seconds. The default time is 60 seconds. If you enter a value smaller than 60 seconds be aware that this can and will affect convergence at scale. This command is not VRF-aware, using it in VRF context will actually assign to the default VRF instead.

keep-alive-timer (1-65535)

  Modify the timeout value for an S,G flow from 1-65535 seconds. If choosing a value below 31 seconds be aware that some hardware platforms cannot see data flowing in better than 30 second chunks. This command is VRF-aware.

packets (1-255)

  When processing packets from a neighbor process the number of packets incoming at one time before moving on to the next task. The default value is 3 packets. This command is only useful at scale when you can possibly have a large number of PIM control packets flowing. This command is not VRF-aware, using it in VRF context will actually assign to the default VRF instead.

register-suppress-time (1-65535)

  Modify the time that a FHR will suppress sending register messages to the RP. This command is not VRF-aware, using it in VRF context will actually assign to the default VRF instead.

send-v6-secondary

  When sending PIM hello packets tell PIM to send any v6 secondary addresses on the interface. This information is used to allow PIM to use v6 nexthops in it's decision for RPF lookup. This command is VRF-aware.

ssm prefix-list WORD

  Specify a range of group addresses via a prefix-list that forces PIM to never do SM over. This command is VRF-aware.

join-filter route-map RMAP_NAME

  Specify a route-map name to use for filtering incoming PIM joins.

  The following route-map match statements can be used:

  - match ip multicast-group A.B.C.D

  - match ip multicast-group prefix-list IPV4-PREFIX-LIST

  - match ip multicast-source A.B.C.D

  - match ip multicast-source prefix-list IPV4-PREFIX-LIST

  - match multicast-interface INTERFACE-NAME

rpf-lookup-mode MODE [group-list PREFIX_LIST] [source-list PREFIX_LIST]

  MODE sets the method used to perform RPF lookups. Supported modes:

  urib-only

    Performs the lookup on the Unicast RIB. The Multicast RIB is never used.

  mrib-only

    Performs the lookup on the Multicast RIB. The Unicast RIB is never used.

  mrib-then-urib

    Tries to perform the lookup on the Multicast RIB. If any route is found, that route is used. Otherwise, the Unicast RIB is tried.

  lower-distance

    Performs a lookup on the Multicast RIB and Unicast RIB each. The result with the lower administrative distance is used; if they're equal, the Multicast RIB takes precedence.

  longer-prefix

    Performs a lookup on the Multicast RIB and Unicast RIB each. The result with the longer prefix length is used; if they're equal, the Multicast RIB takes precedence.

    The `mrib-then-urib` setting is the default behavior if nothing is configured. If this is the desired behavior, it should be explicitly configured to make the configuration immune against possible changes in what the default behavior is.

  If a group and/or source prefix list is provided, then the RPF lookup mode will only apply to source, group addresses that match the given prefix list(s). Not all RPF lookups have a valid group address when performing a lookup, e.g. RPF to an RP only does a lookup to the RP address and has no specific group. Lookups that do not have a specific group will only use lookup modes that do not specify a group-list. A global rpf lookup mode that does not have a group or source list is always installed and, as documented above, uses the `mrib-then-urib` mode by default. This can be changed with an rpf-lookup-mode MODE that does not specify group or source lists. There can be any number of rpf lookup modes, as long as the combination of group and source list is unique.

Warning

Unreachable routes do not receive special treatment and do not cause fallback to a second lookup.

## Global Multicast

These commands are valid at the top-level of the configuration (or also per VRF where indicated), instead of under the 'router pim' submode.

ip igmp generate-query-once [version (2-3)]

  Generate IGMP query (v2/v3) on user requirement. This will not depend on the existing IGMP general query timer. If no version is provided in the cli, the default will be the IGMP version enabled on that interface.

ip igmp watermark-warn (1-65535)

  Configure watermark warning generation for an IGMP group limit. Generates a warning once the configured group limit is reached while adding new groups. The `no` form of the command disables the warning generation. This command is VRF-aware.

### Multicast RIB Commands

The Multicast RIB provides a separate table of unicast destinations which is used for Multicast Reverse Path Forwarding decisions. It is used with a multicast source's IP address, hence contains not multicast group addresses but unicast addresses.

This table is fully separate from the default unicast table. However, RPF lookup can include the unicast table.

ip mroute PREFIX NEXTHOP [DISTANCE]

  Adds a static route entry to the Multicast RIB. This performs exactly as the `ip route` command, except that it inserts the route in the Multicast RIB instead of the Unicast RIB. These routes are only used for RPF lookup and will not be used by zebra for insertion into the kernel or for normal rib processing. As such it is possible to create weird states with these commands. Use with caution. Most of the time this will not be necessary.

show [ip|ipv6] rpf

  Prints the entire Multicast RIB. Note that this is independent of the configured RPF lookup mode, the Multicast RIB may be printed yet not used at all.

show [ip|ipv6] rpf ADDR

  Performs a Multicast RPF lookup using the Multicast RIB only. ADDR specifies the multicast source address to look up. Note that this is independent of the configured RPF lookup mode.

      > show ip rpf 192.0.2.1
      Routing entry for 192.0.2.0/24 using Multicast RIB
      Known via "kernel", distance 0, metric 0, best
      * 198.51.100.1, via eth0

  Indicates that a multicast source lookup for 192.0.2.1 against the Multicast RIB would use an entry for 192.0.2.0/24 with a gateway of 198.51.100.1.

show ip pim [vrf NAME] nexthop-lookup ADDR [GROUP]

  Performs a nexthop lookup according to the configured RPF lookup mode. This performs the lookup for a given source address, and optionally with a group address, which may effect the nexthop decision.

      > show ip pim nexthop-lookup 192.0.2.1
      (192.0.2.1, *) --- Nexthop 198.10.10.1 Interface eth1

  Indicates the a source lookup for 192.0.2.1 according to the configured RPF lookup mode would use the gateway address 192.10.10.1 on interface eth1.

## PIM Interface Configuration

PIM interface commands allow you to configure an interface as either a Receiver or an interface that you would like to form PIM neighborships on. If the interface is in a VRF, enter the interface command with the `vrf` keyword at the end.

ip pim allow-rp [rp-list PLIST]

  When processing a (*,G) source list entry for a particular group in a Join message, RFC 7761 dictates that the source address must be set to the RP address. In some network designs, the sending router's idea of the RP for a particular group may not match ours. Enabling this knob disables checking that the source address in (*,G) source list entries are equal to our RP address for that group. The RP specified in the source list entry is ignored and our RP address is used to join that group.

  Optionally, a prefix-list may be specified; only RP addresses permitted by this prefix-list will be accepted.

ip pim active-active

  Turn on PIM active-active configuration for a Vxlan interface. This command will not do anything if you do not have the underlying ability of a MLAG implementation.

ip pim bsm

  Tell PIM that we would like to use this interface to process bootstrap messages. This is enabled by default. The 'no' form of this command is used to restrict BSM messages on this interface.

ip pim unicast-bsm

  Tell PIM that we would like to allow interface to process unicast bootstrap messages. This is enabled by default. The 'no' form of this command is used to restrict processing of unicast BSM messages on this interface.

ip pim drpriority (0-4294967295)

  Set the DR Priority for the interface. This command is useful to allow the user to influence what node becomes the DR for a LAN segment.

ip pim hello (1-65535) (1-65535)

  Set the PIM hello and hold interval for an interface.

ip pim join-prune-interval (5-600)

  Modify the join/prune interval that PIM uses on this interface. Defaults to the globally configured value (which in turn defaults to 60 seconds). If you enter a value smaller than 60 seconds be aware that this can and will affect convergence at scale.

ip pim assert-interval (1000-86400000)

  Modify the PIM assert interval in milliseconds on this interface (defaults to 18000).

ip pim assert-override-interval (1000-86400000)

  Modify the PIM assert override interval in milliseconds on this interface (defaults to 3000).

ip pim override-interval (0-65535)

  Modify the PIM LAN prune delay override interval in milliseconds on this interface (defaults to 2500).

ip pim [sm | dm | sm-dm]

  Enable PIM on this interface. PIM will use this interface to form PIM neighborships and start exchanging PIM protocol messages with those neighbors. The available modes of operation are:

  `sm` Sparse mode. All groups are forwarded following PIM-SM protocol. This is the default mode if not specified.

  `dm` Dense mode. All groups are forwarded following PIM-DM protocol only. If a dm prefix-list is configured, then groups not matching the prefix list will not be forwarded.

  `sm-dm` Sparse-dense mode. If a group has a RP discovered/configured, then it is forwarded using PIM-SM (even if the RP is currently unreachable), otherwise it is forwarded using PIM-DM. If a dm prefix-list is configured, then groups not matching the list will still be forwarded using PIM-SM even if no RP is available.

  Regardless of the PIM mode, any group matching the SSM range (default 232.0.0.0/8) will be forwarded following the PIM-SSM protocol.

  Please note that this command does not enable the reception of IGMP reports on the interface. Refer to the `ip igmp` command for IGMP management.

ip pim ssm prefix-list PREFIX_LIST

  Configure the Source-Specific-Multicast group range. Defaults to 232.0.0.0/8. Any group within this range will always be treated as SSM.

ip pim dm prefix-list PREFIX_LIST

  Limit dense mode multicast to the range configured with prefix-list. By default there is no limit. This is primarily used for interfaces in sparse-dense mode to limit which groups are forwarded in dense mode when no RP is available for the group. If this list is configured and an interface is in dense mode only, it will not forward groups that do not match the prefix list.

ip pim allowed-neighbors prefix-list PREFIX_LIST

  Only establish sessions with PIM neighbors allowed by the prefix-list.

ip pim use-source A.B.C.D

  If you have multiple addresses configured on a particular interface and would like PIM to use a specific source address associated with that interface.

ip pim passive

  Disable sending and receiving PIM control packets on the interface.

ip igmp

  Tell PIM to receive IGMP reports and Query on this interface. The default version is v3. This command is useful on a LHR.

ip igmp require-router-alert

  Only accept IGMP reports with the router-alert IP option.

ip igmp join-group A.B.C.D [A.B.C.D]

  Join multicast group or source-group on an interface. This will result in an IGMP join happening through a local socket so that IGMP reports will be sent on this interface. It may also have the side effect of the kernel forwarding multicast traffic to the socket unnecessarily.

ip igmp static-group A.B.C.D [A.B.C.D]

  Add a static multicast group or source-group on an interface. This will behave as if there is a receiver on this interface without any IGMP reports.

ip igmp proxy

  Tell PIM to send proxy IGMP reports for joins occurring on all other interfaces on this interface. Join-groups on other interfaces will also be proxied. The default version is v3.

ip igmp proxy route-map ROUTE-MAP

  Apply a route-map to filter which multicast (S,G) entries are forwarded via IGMP proxy on this interface. Only groups permitted by the route-map will be proxied; all others are silently dropped.

  This is evaluated at proxy join time: on initial proxy setup (`ip igmp proxy`) and each time a new IGMP report arrives on another interface. Changing the route-map takes effect on the next proxy enable/disable cycle.

  The following `match` statements are supported:

  - `match ip multicast-group A.B.C.D`

  - `match ip multicast-group prefix-list PREFIX-LIST`

  - `match ip multicast-source A.B.C.D`

  - `match ip multicast-source prefix-list PREFIX-LIST`

  - `match multicast-interface INTERFACE-NAME`

  - `match multicast-source-interface INTERFACE-NAME`

  `match multicast-source-interface` matches against the inbound interface for the filter decision. In a proxy filter that is the interface where the IGMP/MLD report was received (the upstream/listener-facing interface), which is distinct from the proxy output interface. In a regular `ip/ipv6 igmp/mld route-map` (or a PIM `join-filter`) it is the interface processing the report or join, in which case it behaves the same as `match multicast-interface`.

  This allows filtering proxy joins per source interface:

      route-map PROXY_FILTER permit 10
       match multicast-source-interface eth0

      interface eth1
       ip igmp proxy
       ip igmp proxy route-map PROXY_FILTER

  With this configuration, only groups reported on `eth0` are proxied out `eth1`.

  Indirect IGMPv2 vs IGMPv3 filtering

  There is no explicit `match igmp-version` condition, but IGMP version can be distinguished indirectly through the source address:

  - IGMPv2 joins and IGMPv3 ASM `(*,G)` reports both produce entries with source `0.0.0.0` (wildcard).

  - IGMPv3 SSM `(S,G)` reports carry a specific non-zero source address.

  To proxy only IGMPv3 SSM joins (deny any-source entries):

      ip prefix-list ANY_SOURCE seq 5 permit 0.0.0.0/32

      route-map PROXY_SSM_ONLY deny 10
       match ip multicast-source prefix-list ANY_SOURCE
      route-map PROXY_SSM_ONLY permit 20

      interface eth1
       ip igmp proxy
       ip igmp proxy route-map PROXY_SSM_ONLY

  To proxy only ASM / IGMPv2-style `(*,G)` entries (deny SSM):

      ip prefix-list ANY_SOURCE seq 5 permit 0.0.0.0/32

      route-map PROXY_ASM_ONLY permit 10
       match ip multicast-source prefix-list ANY_SOURCE

      interface eth1
       ip igmp proxy
       ip igmp proxy route-map PROXY_ASM_ONLY

  Example — proxy only groups in 239.0.0.0/8:

      ip prefix-list PROXY_GROUPS seq 5 permit 239.0.0.0/8 le 32

      route-map PROXY_FILTER permit 10
       match ip multicast-group prefix-list PROXY_GROUPS

      interface eth1
       ip igmp proxy
       ip igmp proxy route-map PROXY_FILTER

ip igmp immediate-leave

  Immediately leaves an IGMP group when receiving a IGMPv2 Leave packet.

ip igmp query-interval (1-65535)

  Set the IGMP query interval that PIM will use.

ip igmp query-max-response-time (1-65535)

  Set the IGMP query response timeout value. If an report is not returned in the specified time we will assume the S,G or *,G has timed out.

ip igmp version (2-3)

  Set the IGMP version used on this interface. The default value is 3.

ip igmp max-groups (0-4294967295)

  Set the maximum number of IGMP groups that the can be joined on an interface.

ip igmp max-sources (0-4294967295)

  Set the maximum number of IGMP sources to learn per group.

ip multicast boundary oil WORD

  Set a PIM multicast boundary, based upon the WORD prefix-list. If a PIM join or IGMP report is received on this interface and the group is denied by the prefix-list, PIM will ignore the join or report.

      prefix-list multicast-acl seq 5 permit 232.1.1.1/32
      prefix-list multicast-acl seq 10 deny 232.1.1.0/24
      prefix-list multicast-acl seq 15 permit any
      !
      interface r1-eth0
       ip pim
       ip igmp
       ip multicast boundary oil multicast-acl
      exit

ip multicast boundary ACCESS-LIST

  Set a PIM multicast boundary, based upon the ACCESS-LIST. If a PIM join or IGMP report is received on this interface and the (S,G) tuple is denied by the access-list, PIM will ignore the join or report.

  To filter on both source and group, the extended access-list syntax must be used.

  If both a prefix-list and access-list are configured for multicast boundaries, the prefix-list will be evaluated first (and must have a terminating "permit any" in order to also evaluate against the access-list).

      access-list multicast-acl seq 5 permit ip host 10.0.20.2 host 232.1.1.1
      access-list multicast-acl seq 10 deny ip 10.0.20.0 0.0.0.255 232.1.1.0 0.0.0.255
      access-list multicast-acl seq 15 permit ip any any
      !
      interface r1-eth0
       ip pim
       ip igmp
       ip multicast boundary pim-acl
      exit

ip igmp robustness (1-255)

  Set the IGMP robustness value. The default value is 2. 'no' form of this command is used to to configure back to the default value.

ip igmp last-member-query-count (1-255)

  Set the IGMP last member query count. The default value is the currently configured robustness value. 'no' form of this command is used to to configure back to the default value.

ip igmp last-member-query-interval (1-65535)

  Set the IGMP last member query interval in deciseconds. The default value is 10 deciseconds. 'no' form of this command is used to to configure back to the default value.

ip mroute INTERFACE A.B.C.D [A.B.C.D]

  Set a static multicast route for a traffic coming on the current interface to be forwarded on the given interface if the traffic matches the group address and optionally the source address.

ip igmp access-list ACCESSLIST4_NAME

  Apply the indicated access list to filter incoming IGMP joins.

ip igmp route-map ROUTE-MAP

  Apply the indicated route map to filter incoming IGMP joins.

  The following match statements can be used:

  - match ip multicast-group A.B.C.D

  - match ip multicast-group prefix-list IPV4-PREFIX-LIST

  - match ip multicast-source A.B.C.D

  - match ip multicast-source prefix-list IPV4-PREFIX-LIST

  - match multicast-interface INTERFACE-NAME

See also

PIM BFD Configuration

## Multicast Source Discovery Protocol (MSDP) Configuration

MSDP can be setup in different ways:

- MSDP meshed-group: where all peers are connected with each other creating a fully meshed network. SAs (source active) messages are not forwarded in this mode because the origin is able to send SAs to all members.

  This setup is commonly used with anycast.

- MSDP peering: when there is one or more peers that are not fully meshed. SAs may be forwarded depending on the result of filtering and RPF checks.

  This setup is commonly consistent with BGP peerings (for RPF checks).

- MSDP default peer: there is only one peer and all SAs will be forwarded there.

Note

MSDP default peer is not implemented.

### Commands available for MSDP

Note

MSDP configuration is available under 'router pim'.

msdp timers (1-65535) (1-65535) [(1-65535)]

  Configure global MSDP timers.

  First value is the keep-alive interval. This configures the interval in seconds between keep-alive messages. The default value is 60 seconds. It should be less than the remote hold time.

  Second value is the hold-time. This configures the interval in seconds before closing a non responding connection. The default value is 75. This value should be greater than the remote keep alive time.

  Third value is the connection retry interval and it is optional. This configures the interval between connection attempts. The default value is 30 seconds.

msdp mesh-group WORD member A.B.C.D

  Create or update a mesh group to include the specified MSDP peer.

msdp mesh-group WORD source A.B.C.D

  Create or update a mesh group to set the source address used to connect to peers.

msdp peer A.B.C.D source A.B.C.D [as AS_NUMBER]

  Create a regular MSDP session with peer using the specified source address.

  Optionally the Autonomous Number (AS) can be provided for eBGP assisted loop detection (see RFC 4611 Section 2.1. Peering between PIM Border Routers).

  Note

  The BGP configuration must be enabled in order for this feature to work:

      bgp send-extra-data zebra

  This knob causes BGP to send the AS Path information to `zebra` so MSDP can use that information.

msdp peer A.B.C.D sa-filter ACL_NAME <in|out>

  Configure incoming or outgoing SA filtering rule.

  Note

  The filtering will only take effect starting from the command application.

msdp peer A.B.C.D sa-limit <AMOUNT>

  Configure the maximum number of SAs to learn from peer.

msdp peer A.B.C.D password WORD

  Use MD5 authentication to connect with the remote peer.

  Note

  The authentication will only take effect when starting a new connection.

  To apply it immediately call clear ip msdp peer A.B.C.D.

msdp originator-id A.B.C.D

  Use the specified originator ID instead of the multicast RP group.

msdp shutdown

  Shutdown the MSDP sessions in this PIM instance.

## Show PIM Information

All PIM show commands are VRF-aware and typically allow you to add a `vrf` option if information is desired about a specific VRF. If no VRF is specified then the default VRF is assumed. Finally the special keyword `all` allows you to look at all VRFs for the command. Naming a VRF `all` will cause great confusion.

show ip igmp interface

  Display IGMP interface information.

show ip igmp [vrf NAME] join [json]

  Display IGMP static join information.

show ip igmp [vrf NAME] groups [INTERFACE [GROUP]] [detail] [json]

  Display IGMP groups information.

show ip igmp groups retransmissions

  Display IGMP group retransmission information.

show ip igmp [vrf NAME] proxy [json]

  Display IGMP proxy join information.

show ip igmp [vrf NAME] sources [json]

  Display IGMP sources information.

show ip igmp sources retransmissions

  Display IGMP source retransmission information.

show ip igmp statistics

  Display IGMP statistics information.

show ip multicast

  Display various information about the interfaces used in this PIM instance.

show ip mroute [vrf NAME] [A.B.C.D [A.B.C.D]] [fill] [json]

  Display information about installed into the kernel S,G mroutes. If one address is specified we assume it is the Group we are interested in displaying data on. If the second address is specified then it is Source Group. The keyword fill says to fill in all assumed data for test/data gathering purposes.

show ip mroute [vrf NAME] count [json]

  Display information about installed into the kernel S,G mroutes and in addition display data about packet flow for the mroutes for a specific VRF.

show ip mroute vrf all count [json]

  Display information about installed into the kernel S,G mroutes and in addition display data about packet flow for the mroutes for all VRFs.

show ip mroute [vrf NAME] summary [json]

  Display total number of S,G mroutes and number of S,G mroutes installed into the kernel for a specific VRF.

show ip mroute vrf all summary [json]

  Display total number of S,G mroutes and number of S,G mroutes installed into the kernel for all VRFs.

show ip msdp mesh-group

  Display the configured mesh-groups, the local address associated with each mesh-group, the peer members included in each mesh-group, and their status.

show ip msdp peer

  Display information about the MSDP peers. That includes the peer address, the local address used to establish the connection to the peer, the connection status, and the number of active sources.

show ip pim assert

  Display information about asserts in the PIM system for S,G mroutes. This command does not show S,G Channel states that in a NOINFO state.

show ip pim assert-internal

  Display internal assert state for S,G mroutes

show ip pim assert-metric

  Display metric information about assert state for S,G mroutes

show ip pim assert-winner-metric

  Display winner metric for assert state for S,G mroutes

show ip pim group-type

  Display SSM group ranges.

show ip pim interface

  Display information about interfaces PIM is using.

show ip pim mlag [vrf NAME|all] interface [detail|WORD] [json]

  Display MLAG interface information.

show ip pim join

  Display information about PIM joins received. If one address is specified then we assume it is the Group we are interested in displaying data on. If the second address is specified then it is Source Group.

show ip pim local-membership

  Display information about PIM interface local-membership.

show ip pim mlag summary [json]

  Display MLAG information state that PIM is keeping track of.

show ip pim neighbor

  Display information about PIM neighbors.

show ip pim nexthop

  Display information about pim nexthops that are being used.

show ip pim nexthop-lookup

  Display information about an S,G pair and how the RPF would be chosen. This is especially useful if there are ECMP's available from the RPF lookup.

show ip pim [vrf NAME] rp-info [A.B.C.D/M] [json]

  Display information about RP's that are configured on this router.

  You can filter the output by specifying an arbitrary group range.

      # show ip pim rp-info
      RP address       group/prefix-list   OIF               I am RP    Source   Group-Type
      192.168.10.123   225.0.0.0/24        eth2              yes        Static   ASM
      192.168.10.123   239.0.0.0/8         eth2              yes        Static   ASM
      192.168.10.123   239.4.0.0/24        eth2              yes        Static   SSM

      # show ip pim rp-info 239.4.0.0/25
      RP address       group/prefix-list   OIF               I am RP    Source   Group-Type
      192.168.10.123   239.0.0.0/8         eth2              yes        Static   ASM
      192.168.10.123   239.4.0.0/24        eth2              yes        Static   SSM

show ip pim [vrf NAME] autorp [json]

  Display information about AutoRP. Including state of AutoRP Discovery parsing and configured AutoRP candidate RP information.

show ip pim rpf

  Display information about currently being used S,G's and their RPF lookup information. Additionally display some statistics about what has been happening on the router.

show ip pim secondary

  Display information about an interface and all the secondary addresses associated with it.

show ip pim state

  Display information about known S,G's and incoming interface as well as the OIL and how they were chosen.

show ip pim [vrf NAME] upstream [A.B.C.D [A.B.C.D]] [json]

  Display upstream information about an S,G mroute. Allow the user to specify sub Source and Groups that we are only interested in.

show ip pim upstream-join-desired

  Display upstream information for S,G's and if we desire to join the multicast tree

show ip pim upstream-rpf

  Display upstream information for S,G's and the RPF data associated with them.

show ip pim [vrf NAME] mlag upstream [A.B.C.D [A.B.C.D]] [json]

  Display upstream entries that are synced across MLAG switches. Allow the user to specify sub Source and Groups address filters.

show ip pim mlag summary

  Display PIM MLAG (multi-chassis link aggregation) session status and control message statistics.

show ip pim bsr [vrf NAME] [json]

  Display current bsr, its uptime and last received bsm age.

show ip pim bsr candidate-bsr [vrf NAME] [json]

  Display information about the candidate BSR state on this router.

show ip pim bsr candidate-rp [vrf NAME] [json]

  Display information about the candidate RP state on this router.

show ip pim bsr candidate-rp-database [vrf NAME] [json]

  Display the current list of candidate RPs received by this router.

show ip pim bsr groups [vrf NAME] [json]

  Display the current list of multicast group mapping received by this router from candidate RPs.

show ip pim bsr rp-info [vrf NAME] [json]

  Display group-to-rp mappings received from E-BSR.

show ip pim bsm-database [vrf NAME] [json]

  Display all fragments of stored bootstrap message in user readable format.

mtrace A.B.C.D [A.B.C.D]

  Display multicast traceroute towards source, optionally for particular group.

show ip multicast count [vrf NAME] [json]

  Display multicast data packets count per interface for a VRF.

show ip multicast count vrf all [json]

  Display multicast data packets count per interface for all VRF.

See also

Multicast RIB Commands

## PIM Debug Commands

The debugging subsystem for PIM behaves in accordance with how FRR handles debugging. You can specify debugging at the enable CLI mode as well as the configure CLI mode. If you specify debug commands in the configuration cli mode, the debug commands can be persistent across restarts of the FRR pimd if the config was written out.

debug igmp

  This turns on debugging for IGMP protocol activity.

debug mtrace

  This turns on debugging for mtrace protocol activity.

debug mroute

  This turns on debugging for PIM interaction with kernel MFC cache.

debug pim events

  This turns on debugging for PIM system events. Especially timers.

debug pim nht

  This turns on debugging for PIM nexthop tracking. It will display information about RPF lookups and information about when a nexthop changes.

debug pim nht detail

  This turns on debugging for PIM nexthop in detail. This is not enabled by default.

debug pim graft

  This turns on debugging for PIM graft message processing. Graft messages are similar to PIM joins but are specifically used for PIM dense mode. This is not enabled by default.

debug pim state-refresh

  This turns on debugging for PIM state-refresh message processing. State-refresh messages are used in PIM dense mode. This is not enabled by default.

debug pim packet-dump

  This turns on an extraordinary amount of data. Each pim packet sent and received is dumped for debugging purposes. This should be considered a developer only command.

debug pim packets

  This turns on information about packet generation for sending and about packet handling from a received packet.

debug pim trace

  This traces PIM code and how it is running.

debug pim bsm

  This turns on debugging for BSR message processing.

debug pim zebra

  This gathers data about events from zebra that come up through the ZAPI.

debug pim autorp

  This turns on debugging for PIM AutoRP protocol events.

## PIM Clear Commands

Clear commands reset various variables.

clear ip interfaces

  Reset interfaces.

clear ip igmp interfaces

  Reset IGMP interfaces.

clear ip mroute

  Reset multicast routes.

clear ip mroute [vrf NAME] count

  When this command is issued, reset the counts of data shown for packet count, byte count and wrong interface to 0 and start count up from this spot.

clear ip pim interfaces

  Reset PIM interfaces.

clear ip pim oil

  Rescan PIM OIL (output interface list).

clear ip pim [vrf NAME] bsr-data

  This command will clear the BSM scope data struct. This command also removes the next hop tracking for the bsr and resets the upstreams for the dynamically learnt RPs.

clear ip msdp peer A.B.C.D

  Reset MSDP peer connection.

  Use this command to set/unset MD5 authentication.

clear ip msdp [vrf all|vrf VRF_NAME] peer [A.B.C.D] counters

  Reset the MSDP peer(s) statistic counters.

## PIM EVPN configuration

To use PIM in the underlay for overlay BUM forwarding associate a multicast group with the L2 VNI. The actual configuration is based on your distribution. Here is an ifupdown2 example:

    auto vx-10100
    iface vx-10100
        vxlan-id 10100
        bridge-access 100
        vxlan-local-tunnelip 27.0.0.11
        vxlan-mcastgrp 239.1.1.100

Note

PIM will see the `vxlan-mcastgrp` configuration and auto configure state to properly forward BUM traffic.

PIM also needs to be configured in the underlay to allow the BUM MDT to be setup. This is existing PIM configuration:

- Enable PIM on the underlay L3 interface via the "ip pim" command.

- Configure RPs for the BUM multicast group range.

- Ensure the PIM is enabled on the lo of the VTEPs and the RP.

## Sample configuration

    debug igmp
    debug pim
    debug pim zebra

    ! You may want to enable ssmpingd for troubleshooting
    ! See http://www.venaas.no/multicast/ssmping/
    !
    router pim
     ssmpingd 1.1.1.1
     ssmpingd 2.2.2.2

    ! HINTS:
    !  - Enable "ip pim ssm" on the interface directly attached to the
    !    multicast source host (if this is the first-hop router)
    !  - Enable "ip pim ssm" on PIM-routers-facing interfaces
    !  - Enable "ip igmp" on IGMPv3-hosts-facing interfaces
    !  - In order to inject IGMPv3 local membership information in the
    !    PIM protocol state, enable both "ip pim ssm" and "ip igmp" on
    !    the same interface; otherwise PIM won't advertise
    !    IGMPv3-learned membership to other PIM routers

    interface eth0
     ip pim ssm
     ip igmp