Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

The proxy ARP feature in the PIX 500 Series Firewall with software version 6.x creates communication issues in the local LAN

Core issue

This problem occurs because earlier versions of the PIX Firewall had a very aggressive proxy Address Resolution Protocol (ARP), so the device replied to every ARP with its own address. This situation causes communication issues in the local LAN segment.

The immediate effect of this problem is that no one in the local LAN segment can see each other.


For a workaround,

Disable the proxy ARP feature on the inside interface of the PIX.

To do this, issue the following command in configuration mode:

hostname(config)# sysopt noproxyarp < interface_name >

As an alternative, upgrade to the latest software image.

Refer to step11 in Troubleshooting Connectivity Problems section of Establish and Troubleshoot Connectivity through the Cisco Security Appliance

Version history
Revision #:
1 of 1
Last update:
‎06-22-2009 04:07 PM
Updated by:
Labels (1)