Proxy ARP

[gregth1978]

Iwould like to know if the 800 Series router supports Proxy ARP. I have been told that any router using IOS will do it but I have been unable to find documentation that confirms this.

Thanks

[Patrick Iseli]

Command reference:

Enabling Proxy ARP

The Cisco IOS software uses proxy ARP (as defined in RFC 1027) to help hosts with no knowledge of routing determine the media addresses of hosts on other networks or subnets. For example, if the router receives an ARP request for a host that is not on the same interface as the ARP request sender, and if the router has all of its routes to that host through other interfaces, then it generates a proxy ARP reply packet giving its own local data-link address. The host that sent the ARP request then sends its packets to the router, which forwards them to the intended host. Proxy ARP is enabled by default.

To enable proxy ARP if it has been disabled, use the following command in interface configuration mode (as needed) for your network:

Router(config-if)# ip proxy-arp

Enables proxy ARP on the interface.

Configuring Address Resolution Methods

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a00800ca75b.html

hope that helps

Patrick

[Richard Burts]

I do not have an 800 series router to test with, but I am pretty sure that it does support Proxy ARP. I recently was involved in a problem situation which was caused when someone disabled Proxy ARP on a 1700 series router. (The problem was solved when we enabled again Proxy ARP.)

One easy way to investigate this is to do show ip interface . There should be a line in the display which indicates that Proxy ARP is enabled or disabled.

HTH

Rick