5
Figure 4 Inter-site unicast
Flood
The VTEP floods a broadcast, multicast, or unknown unicast frame to all site-facing interfaces and
VXLAN tunnels in the VXLAN, except for the incoming interface.
VXLAN supports the following modes for flood traffic:
•
Unicast
mode
—Also called head-end replication. The source VTEP replicates the flood frame,
and then sends one replica to the destination IP address of each VXLAN tunnel in the VXLAN.
See
.
•
Multicast
mode
—Also called tandem replication. The source VTEP sends the flood frame in a
multicast VXLAN packet destined for a multicast group address. Transport network devices
replicate and forward the packet to remote VTEPs based on their multicast forwarding entries.
See
.
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.
