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 unicast mode for flood traffic. The mode is 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
.
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.
Figure 5 Unicast mode
VTEP 1
VTEP 2
Transport network
P
Terminal 1
Terminal 2
Terminal 3
Terminal 7
Terminal 8
Terminal 9
Terminal 4
Terminal 5
Terminal 6
VX
LA
N tu
nne
l
VX
LA
N
tun
ne
l
VTEP 3
VXLAN tunnel
Terminal 10
Terminal 11
Terminal 12
Replicate and
encapsulate
