H3C LS-3100-52P-OVS-H3 Operation Manual - page 344
2-2
You can solve the problem by enabling proxy ARP on Switch. After that, Switch can reply to the ARP
request from Host A with the MAC address of VLAN-interface 1, and forward packets sent from Host A
to Host B. In this case, Switch seems to be a proxy of Host B.
A main advantage of proxy ARP is that it is added on a single router without disturbing routing tables of
other routers in the network. Proxy ARP acts as the gateway for IP hosts that are not configured with a
default gateway or do not have routing capability.
Local Proxy ARP
As shown in
Figure 2-2
, 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 to allow Layer 3 communication between the two hosts.
Figure 2-2 Application environment of local proxy ARP
In one of the following cases, you need to enable local proxy ARP:
z
Hosts connecting to different isolated Layer 2 ports in the same VLAN need to communicate at
Layer 3.
z
If an isolate-user-vlan is configured, hosts in different secondary VLANs of the isolate-user-vlan
need to communicate at Layer 3.
Enabling Proxy ARP
Follow these steps to enable proxy ARP in VLAN interface view:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter interface view
interface interface-type interface-number
Required
Enable proxy ARP
proxy-arp enable
Required
Disabled by default.
Follow these steps to enable local proxy ARP in VLAN interface view:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter interface view
interface interface-type interface-number
Required