In multicast VXLAN, the VNI is mapped to a multicast group and multicast tunnels are used to distribute broadcast, unknown unicast and multicast (BUM) tenant traffic to remote endpoints (VTEPs). This requires that the Layer 3 network supports multicast.
Unicast VXLAN uses unicast tunnels, and the BUM traffic is head-end replicated to each of the remote endpoints
Note
ExtremeXOS implements only unicast VXLAN.