Local proxy ARP
As shown in Figure 7, Host A and Host B belong to VLAN 2, but are isolated at Layer 2. Host A connects to GigabitEthernet 1/0/3 while Host B connects to GigabitEthernet 1/0/1. Enable local proxy ARP on Switch A to allow Layer 3 communication between the two hosts.
Figure 7: Application environment of local proxy ARP
Enable local proxy ARP in one of the following cases:
Hosts connecting to different isolated Layer 2 ports in the same VLAN need to communicate at Layer 3.
If a super VLAN is configured, hosts in different sub VLANs of the super VLAN need to communicate at Layer 3.
If an isolate-user-VLAN is configured, hosts in different secondary VLANs of the isolate-user-VLAN need to communicate at Layer 3.