Address Resolution Protocol (ARP) Learning over Tunnels

Layer 3 gateways support learning ARP entries for neighbors reachable through a tunnel. Gateways process ARP requests that ingress the switch from a tunnel, and respond to those requests by sending unicast ARP responses over the tunnel. Similarly, gateways broadcast ARP requests to both physical ports and tunnels and process ARP responses received from a neighbor that is reachable through a tunnel.

For VXLAN MLAG configurations, ExtremeXOS 30.5 supports checkpointing of ARP entries learned on the checkpoint-able VXLAN tenant VLAN to the MLAG peer. This helps in avoiding unwanted flooding of ARP requests when the request hashes to the MLAG peers that do not have the ARP entries learned from the tunnel. It also avoids unwanted flooding when the peer that has the ARP reboots.