|Hmm, ok, let me explain the situation a bit more. I made a picture available here:|
So, if a computer is in zone B, the restricted zone, it can access the internet with no problem, but all serverrelated programs don't work, because you can't connect to this computer from the internet.
However, if a computer is in zone C, a non-restricted zone, it is possible to connect to it from the internet without any problems.
The part where this gets interesting is, that computers in zone C can connect to servers (like ftp, http, ssh,...) in zone A, the whole campus network.
Most computers from students belong to zone B, but my comuter belongs to zone C.
So I am able to run servers, and use iptables for firewalling.
So what I want to do now, is to 'forward' (or should I say 'lead the way') ftp requests to a specific port to my computer (which is connected to the internet, zone C) to another computer, also connected to the internet, but located in zone B.
The idea behind this is that my computer can accept requests for connection from the internet, and my computer can also connect to servers in zone B. so if my iptables can make the computer on the internet think that it is connecting to my pc, it would be possible to connect to servers in zone B.
I can understand that this is a bit too difficult because both incoming and outgoing traffic from the computer on the internet and the computer in zone B would go through the same network card.
I have 2 NIC's, so I would be able to do some tricky things by connecting twice to the same network, but if it can be done with a few iptable rules, it would be a lot easier
I will look at the ssh tunnels when I have more time.