I posted this in the linux forum a few days ago, but didnt get a response. Maybe somehere can help me out? I am new to Linux and it's firewall, and I am trying to get the TCP packets of a program to go through my proxy server. How exactly do i do this? Is it possible with iptables or ipchains without completly reconfiguring my system as a router? Is there a simple program that can do it? I need to change the destination address and port. I know the address and port the program is sending to and what that needs to be changed to. However, the source port on my machine is randomly selected by the program, so i cannot use a program like desproxy or rinetd. The damn prog simply selects a different port.

First of all, destination ports are on the server. Your Linux box is a client, not a server. Both Unix and Windows use random source ports. You can't change a port on a remote server.

I found a tool you might want to play with. It's called FPipe from www.foundstone.com Go to free tools.

I dont want to change to port on the server, I want to change the outgoing port on my machine based on the destination port

NAT's are really PAT's. Not only can you change network address but you can change network ports with a NAT. All linux distro's can be setup to run a nat. Almost all newer home/SOHO internet router's support complex natting. You can even run a linux virtual machine within the linux setup to both firewall and nat.

Look at FPipe that I mentioned in the post above. You can control the source port.