With a VXLAN EVPN fabric (based on N9k), I need to deliver a small amount (1Mbit) of multicast video from a server attached to a leaf out through the spine and border-leaf to our classic-ethernet network. PIM is already enabled on the underlay between leaf/spine/borderleaf, but we are using ingress-replication:
host-reachability protocol bgp
member vni 10010
ingress-replication protocol bgp
member vni 103967 associate-vrf
vrf member vf-cam
no ip redirects
no ipv6 redirects
I thought this would get delivered as broadcast, then at the egress point from the fabric (the border leaf) it would convert to multicast. This isn't happening and there is no PIM mroute entry on the border-leaf. If I want to deliver this traffic, do I really have to roll out TRM?
It looks like Ingress Replication (also known as HER or Head-End Replication) will handle multicast as a layer 2 broadcast only. The frames would get sent from Leaf -> BorderLeaf (assuming the VNI is defined on the border-leaf), but at that point even if a PIM join arrives from the external network, the border leaf won't start routing the traffic.
I believe TRM (Tenant Routed Multicast) is needed, which is a pain as it will involve assigning multicast groups for use in the fabric, and there seems to be a few limitations to check through before deploying that (although things are looking better in nx-os v9.3+).