Figure 4: Forwarding of flood traffic
Forwarding of flood traffic
A VTEP floods a broadcast, multicast, or unknown unicast frame to all site-facing interfaces except for the incoming interface. The source VTEP also replicates the flood frame, and then sends one replica to the destination IP address of each VXLAN tunnel in the VXLAN. Each destination VTEP floods the inner Ethernet frame to all the site-facing interfaces in the VXLAN. To avoid loops, the destination VTEPs do not flood the frame to VXLAN tunnels.

For BUM traffic flooding, only Head End Replication (HER) is supported.