Port Redirect to Inside Host on a Cisco PIX Firewall

Posted September 23, 2004 by lvance in Cisco firewall

This Tech-Recipes tutorial explains how to configure a PIX to redirect traffic to an inside host via port re-direction. An expample would be if you allowed your PIX to get its external address via DHCP, but you wanted to access a ftp server on the inside of your firewall as well as another host for vnc.

First, you have to add a static entry for the host and port redirecting like this:
static (inside,outside) tcp ftp ftp netmask
static (inside,outside) tcp 5900 5900 netmask

Note: The is your outside interface that was assigned via dhcp.

Then you need to build an ACL to allow access through the PIX:

access-list outside-inbound permit tcp any host eq ftp
access-list outside-inbound permit tcp host host eq 5900

Now, you can ftp from anywhere to the outside IP Address of the PIX and be redirected to on the inside ftp server.

You can now also vnc to the outside interface and be redirected to and access that server via vnc.

This is very helpful at times on smaller PIX’s on broadband connections, etc.

The Conversation

Follow the reactions below and share your own thoughts.