VXLAN Multicast

VXLAN Multicast

VXLAN with Multicast control plane is not explicitly stated in JNCIE-DC lab exam topics, so I not expect it on the exam.

But anyway I decided to start Overlay topics from the simple case and later on continue to more advanced ones.

Firstly, for Multicast VXLAN of course you need to configure Multicast protocol in the Underlay. Nothing complex, just basic PIM stuff: configure PIM interfaces and some kind of RP (static/local/anycast-RP).

Configure VTEP source interface:

set switch-options vtep-source-interface lo0.0

Next step is the interface and VLAN config.

QFX style:

interfaces {
    xe-0/0/0 {
        unit 0 {
            family ethernet-switching {
                interface-mode trunk;
                vlan {
                    members v100;
                }
            }
        }
    }
}
vlans {
    v100 {
        vlan-id 100;
        vxlan {
            vni 100;
            multicast-group 239.0.0.1;
        }
    }
}


MX style:

interfaces {
    ge-0/0/0 {
        vlan-tagging;
        encapsulation flexible-ethernet-services;
        unit 0 {
            encapsulation vlan-bridge;
            vlan-id 100;
            }
        }
    }
}
bridge-domains {
    v100 {
        vlan-id 100;
        vxlan {
            vni 100;
            multicast-group 239.0.0.1;
        }
    }
}


Yes, thats all, so easy. Just add VXLAN VNI and corresponding multicast-group address to vlan/bridge-domain config.

MX IRB configuration – add routing-interface to bridge-domain:

bridge-domains {
    v100 {
        vlan-id 100;
        routing-interface irb.100;
        vxlan {
            vni 100;
            multicast-group 239.0.0.1;
        }
    }
}

set interfaces irb unit 100 family inet … vrrp …


Remember – QFX5100 doesn’t support Inter-VXLAN routing!

To support double tags over VXLAN tunnels:

QFX:    set vlans v100 vxlan encapsulate-inner-vlan
        set protocols l2-learning decapsulate-accept-inner-vlan
MX:     set bridge-domains v100 vxlan encapsulate-inner-vlan
        set bridge-domains v100 vxlan decapsulate-accept-inner-vlan

And finally some show commands:

QFX:  show ethernet-switching vxlan-tunnel-end-point remote mac-table
MX:   show l2-learning vxlan-tunnel-end-point remote mac-table

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