How to set up a ping tunnel without a host and a proxy

Question

I have been reading about setting up a ping tunnel to access the internet when you can only send ICMP packets. Ptunnel seems to be a popular program and the instructions to use it can be found here http://www.cs.uit.no/~daniels/PingTunnel/. The instructions to this program say that you must have both a client and proxy computer.

I do not understand the benefit of a ping tunnel if you must have a proxy computer that can send TCP/IP packets. If I had a computer that could do that, I wouldn't need to set up the tunnel in the first place. Can someone please explain this to me, why is a proxy necessary and if it is how is ping tunneling useful then?

NSNolan

Answer 1

Well, let's assume you have a server (PC running linux for example) in your home where it has total internet access and now you are at work/airport/hotel with your laptop where you have no access to tcp without paying.By setting an icmp or dns tunnel you can "encode" your packets to appear as if they were pings/nslookup, those packets destination is always your server. When the server recieves those pings from you, it "decodes" them and totally understand what you are trying to reach (like a website or download a file as an example). Then your server serves you and get the information you are seeking and "encode" them again into icmp/nslookup like packets. Those packets can reach you without any problem and once they do, your laptop can decode them back into useful information (just like the ones it would recieve with tcp). That encoding & decoding are what the Ptunnel do. Though I'm not professional I think that is the total point.