IGMP snooping is supported in EVPN-MPLS VPLS and PBB-EVPN I-VPLS (where BGP EVPN is running in the associated B-VPLS service) services. It is also supported in EVPN-MPLS VPRN and IES R-VPLS services. It is required in scenarios where the operator does not want to flood all of the IP multicast traffic to the access nodes or CEs, and only wants to deliver IP multicast traffic for which IGMP reports have been received.
The following points apply when IGMP snooping is configured in EVPN-MPLS VPLS or PBB-EVPN I-VPLS services.
IGMP snooping is enabled using the configure service vpls igmp-snooping no shutdown command.
Queries and reports received on SAP or SDP bindings are snooped and properly handled; they are sent to SAP or SDP bindings as expected.
Queries and reports on EVPN-MPLS or PBB-EVPN B-VPLS destinations are handled as follows.
If received from SAP or SDP bindings, the queries and reports are sent to all EVPN-MPLS and PBB-EVPN B-VPLS destinations, regardless of whether the service is using an ingress replication or mLDP provider tunnel.
If received on an EVPN-MPLS or PBB-EVPN B-VPLS destination, the queries and reports are processed and propagated to access SAP or SDP bindings, regardless of whether the service is using an ingress replication or mLDP provider tunnel.
EVPN-MPLS and PBB-EVPN B-VPLS destinations are is treated as a single IGMP snooping interface and is always added as an mrouter.
The debug trace output displays one copy of messages being sent to all EVPN-MPLS and PBB-EVPN B-VPLS destinations (the trace does not show a copy for each destination) and displays messages received from all EVPN-MPLS and PBB-EVPN B-VPLS destinations as coming from a single EVPN-MPLS interface.
When IGMP snooping is enabled with P2MP LSPs, at least one EVPN-MPLS multicast destination must be established to enable the processing of IGMP messages by the system. The use of P2MP LSPs is not supported when sending IPv4 multicast into an EVPN-MPLS R-VPLS service from its IP interface.
In the following show command output, the EVPN-MPLS destinations are shown as part of the MFIB (when igmp-snooping is in a no shutdown state), and the EVPN-MPLS logical interface is shown as an mrouter.
*A:PE-2# show service id 2000 mfib
===============================================================================
Multicast FIB, Service 2000
===============================================================================
Source Address Group Address SAP or SDP Id Svc Id Fwd
Blk
-------------------------------------------------------------------------------
* * eMpls:192.0.2.3:262132 Local Fwd
eMpls:192.0.2.4:262136 Local Fwd
eMpls:192.0.2.5:262131 Local Fwd
-------------------------------------------------------------------------------
Number of entries: 1
===============================================================================
*A:PE-2# show service id 2000 igmp-snooping base
===============================================================================
IGMP Snooping Base info for service 2000
===============================================================================
Admin State : Up
Querier : 10.0.0.3 on evpn-mpls
-------------------------------------------------------------------------------
SAP or SDP Oper MRtr Pim Send Max Max Max MVR Num
Id Stat Port Port Qrys Grps Srcs Grp From-VPLS Grps
Srcs
-------------------------------------------------------------------------------
sap:1/1/1:2000 Up No No No None None None Local 0
evpn-mpls Up Yes N/A N/A N/A N/A N/A N/A N/A
===============================================================================
*A:PE-4# show service id 2000 igmp-snooping mrouters
===============================================================================
IGMP Snooping Multicast Routers for service 2000
===============================================================================
MRouter SAP or SDP Id Up Time Expires Version
-------------------------------------------------------------------------------
10.0.0.3 evpn-mpls 0d 00:38:49 175s 3
-------------------------------------------------------------------------------
Number of mrouters: 1
===============================================================================
The equivalent output for PBB-EVPN services is similar to the output above for EVPN-MPLS services, with the exception that the EVPN destinations are named "b-EVPN-MPLS".