Allied Telesis AT-8550 - Manual (Page 133)

AT-9108, AT-8518, AT-8525, and AT-8550 User’s Guide
8-5
Proxy ARP
Proxy Address Resolution Protocol (ARP) was first invented so that
ARP-capable devices could respond to ARP Request packets on
behalf of ARP-incapable devices. Proxy ARP can also be used to
achieve router redundancy and simplify IP client configuration. The
switch supports proxy ARP for this type of network configuration. Up
to 64 proxy ARP entries can be configured. The section describes
some example of how to use proxy ARP with the switch.
ARP-Incapable
Devices
To configure the switch to respond to ARP Requests on behalf of
devices that are incapable of doing so, you must configure the IP
address and MAC address of the ARP-incapable device using the use
the following command:
config iparp add proxy {}
{always}
Once configured, the system responds to ARP Requests on behalf of
the device as long as the following conditions are satisfied:
❑ The valid IP ARP Request is received on a router interface.
❑ The target IP address matches the IP address configured in the
proxy ARP table.
❑ The proxy ARP table entry indicates that the system should
always answer this ARP Request, regardless of the ingress
VLAN (the
always parameter must be applied).
Once all the proxy ARP conditions are met, the switch formulates an
ARP Response using the configured MAC address in the packet.