Truly Terrifying Tunneling

It doesn't even end here. Suppose you have no HTTP proxy. Do you have e-mail? That's right. If you simply must connect to the outside world, you can do it by tunneling through e-mail! This is fairly insane, but it can be done. Read about the work of the maniacs behind mailtunnel at: http://www.detached.net/mailtunnel .

We won't cover mailtunnel here. Consider a new job or a new network before you seriously consider tunneling through e-mail.

There's still more. Even if no UDP or TCP traffic is allowed out, it is very possible that ICMP (the protocol used for "ping," Internet Control Message Protocol) does go through. If you can ping the outside world, you can tunnel anything you want. That's right. You can tunnel data in ICMP messages.

Once again, this is so maniacal that we will not cover it in detail. You can read about it from the fine folks at: http://www.detached.net/icmptunnel/ .