iptables firewall and forwarding.

From: Sheldon Lee Wen (sheldon.leewen@cgi.com)
Date: 10/18/02

From: "Sheldon Lee Wen" <sheldon.leewen@cgi.com>
To: focus-linux@securityfocus.com
Date: Fri, 18 Oct 2002 12:07:47 -0400

Hi Everyone,

   I'm in a big bind. Our raptor firewall is toast,

  That said, now my boss wants to put in a linux firewall.

The dev servers are on network xxx.xxx.xxx.xxx and the developer workstations
are on yyy.yyy.yyy.yyy

I have the box on both networks and masquerading, so that you can go from the
developer workstations to the development servers. However, the development
servers use to be on the yyy.yyy.yyy.yyy and the raptor firewall has been
forwarding their old yyy.yyy.yyy.yyy addresses to the xxx.xxx.xxx.xxx
addresses, but the raptor firewall is not the router or gateway for the
yyy.yyy.yyy.yyy network. So, I'm not sure how I can do that on Linux. Has the
raptor firewall been acting as a router as well? Do I need routed on Linux?

How do I do this on linux?