Command Reference Guide

Command Reference Guide Tunnel Configuration Command Set

ip proxy-arp <ip address> <subnet mask>

Use the ip proxy-arp command to enable proxy Address Resolution Protocol (ARP) on the interface. Use

the no form of this command to disable this feature.

Syntax Description

<ip address> Defines the proxy ARP IP address in dotted decimal notation (for example:

192.22.73.101).

<subnet mask> Specifies the subnet mask that corresponds to the listed IP address.

Default Values

By default, proxy-arp is enabled.

Command Modes

(config-interface)# Interface Configuration Mode

Valid interfaces include: Ethernet (eth 0/1), PPP virtual interfaces (ppp 1), HDLC

virtual interfaces (hdlc 1), Frame Relay virtual sub-interfaces (fr 1.20), tunnel

interfaces (tunnel 1), and VLAN interface (vlan 1).

Functional Notes

In general, the principle of proxy ARP allows a router to insert its IP address in the source IP address field

of a packet (if the packet is from a host on one of its subnetworks). This allows hosts to reach devices on

other subnetworks without implementing routing or specifying a default gateway.

If proxy ARP is enabled, the SROS will respond to all proxy ARP requests with its specified MAC address

and forward packets accordingly.

Enabling proxy ARP on an interface may introduce unnecessary ARP traffic on the network.

Usage Examples

The following enables proxy ARP on the tunnel interface:

(config)#interface tunnel 1

(config-tunnel 1)#ip proxy-arp