[EX/QFX] Enabling evpn-ssm-reports-only knob for processing SSM with igmp-snooping enabled in EVPN VXLAN environment

Summary:

The evpn-ssm-reports-only knob is enabled to process SSM (Source Specific multicast) traffic on a leaf or spine in EVPN VXLAN environment.

This article explains where to enable it in case igmp-snooping is being enabled in the leaf/l2 device.

Symptoms:

Usually in EVPN VXLAN environment, if source specific multicast needs to processed, it is mandatory to enable the evpn-ssm-reports-only knob. Refer to evpn-ssm-reports-only for more details.

It works well in MX platforms or when IGMP usenabled. But when IGMP snooping is enabled in QFX/EX which acts as Leaf device (l2 gateway) this is not processed properly.

Cause:

It is not processed if the evpn-ssm-reports-only is enabled in [edit routing-instances routing-instance-name protocols igmp-snooping], as per the above link.

EX9400# show configuration routing-instances EVPN
protocols {
    evpn {
       encapsulation vxlan;
        extended-vni-list all;
        multicast-mode ingress-replication;
    }
    igmp-snooping {
         evpn-ssm-reports-only; <-- This does not work
        vlan all {
       
        }
    }
}

show configuration interfaces ae20   
esi {
    00:03:03:45:06:00:00:60:00:20;
    all-active;
}
aggregated-ether-options {
    lacp {
        active;
        system-id 03:03:45:66:00:20;
    }
}
unit 0 {
    family ethernet-switching {
        interface-mode trunk;
        vlan {
            members 1511;
        }
    }
}

vlans {
   vlan1511 {
       vlan-id 1511
       vxlan { 
           vni 1511
        }
   }
}

Solution:

This knob has to be enabled in[edit routing-instances routing-instance-name protocols igmp-snooping vlan ]. It can enabled for all VLANs as shown below:

EX9400# show configuration routing-instances EVPN
protocols {
    evpn {
         encapsulation vxlan;
        extended-vni-list all;
        multicast-mode ingress-replication;
    }
    igmp-snooping {
              vlan all {
            evpn-ssm-reports-only; <<-- This works and would be enabled for all the vlans
        }
    }
}

Or it can be enabled for individual VLANs as shown below:

EX9400# show configuration routing-instances EVPN
protocols {
    evpn {
         encapsulation vxlan;
        extended-vni-list all;
        multicast-mode ingress-replication;
    }
    igmp-snooping {
              vlan 1511 {
            evpn-ssm-reports-only; <-- This works and would be enabled for vlan 1511
        }
    }
}

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