ip proxy-arp

Enables IP proxy ARP globally.
Syntax
ip proxy-arp
no ip proxy-arp
Command Default

Proxy ARP is disabled by default on Layer 3 switches.

Modes

Global configuration mode

Interface configuration mode

Usage Guidelines

Proxy ARP allows a Layer 3 switch to answer ARP requests from devices on one network on behalf of devices in another network. Because ARP requests are MAC-layer broadcasts, they reach only the devices that are directly connected to the sender of the ARP request. Thus, ARP requests do not cross routers.

An ARP request from one subnet can reach another subnet when both subnets are on the same physical segment (Ethernet cable), because MAC-layer broadcasts reach all the devices on the segment.

This feature is not supported on Layer 2 switches.

The no form of the command disables IP proxy ARP.

Examples

The following example enables IP proxy ARP globally. 

device(config)# ip proxy-arp

The following example enables proxy ARP on port 1/2/1. 

device# configure terminal
device(config)# interface ethernet 1/2/1
device(config-if-e1000-1/2/1)# ip proxy-arp
Parent topic: Commands I