3Com Switch 8800 Advanced Software V5 Configuration Guide

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PROXY ARP CONFIGURATION
When configuring proxy ARP, go to these sections for information you are
interested in:
■ “Proxy ARP Overview” on page 201
■ “Enabling Proxy ARP” on page 201
■ “Displaying and Maintaining Proxy ARP” on page 202
Proxy ARP Overview For an ARP request of a host on a network to be forwarded to an interface that is
on the same network but isolated at Layer 2 or a host on another network, the
device connecting the two physical or virtual networks must be able to respond to
the request. This is achieved by proxy ARP.
Proxy ARP implements Layer 3 communication between interfaces isolated at
Layer 2 or located on different networks.
Proxy ARP involves proxy ARP and local proxy ARP.
In one of the following cases, you need to enable the local proxy ARP:
■ Devices connected to different isolated layer 2 ports in the same VLAN need to
implement layer 3 communication.
■ With the super VLAN function enabled, devices in different sub VLANs need to
implement layer 3 communication.
■ With the isolate-user-vlan function enabled, devices in different second VLANs
need to implement layer 3 communication.
Enabling Proxy ARP Follow these steps to enable proxy ARP or enable local proxy ARP:
To do... Use the command... Remarks
Enter system view system-view -
Enter VLAN interface view interface
vlan-interface-type
interface-number
Required
Enable proxy ARP proxy-arp enable Required
Disabled by default
Enable local proxy ARP local-proxy-arp enable Required
Disabled by default