Tunnelling Through Firewalls

This page describes various tools and techniques for tunnelling your data through firewalls. These techniques are useful primarily from the inside, weak, or "protected side" of the firewall in an attempt to get outside in some manner not directly supported by the firewall. For example, they let you get to your ProShell account with SSH even though your company/school firewall has port 22 blocked.

Once you get SSH through, you can tunnel to our proxies or do whatever else you want to do.

JTAN Provided Service Tunnel Ports

Transparent Tunnels

These are various transparent service tunnels JTAN currently provides. Normally these are useful to puncture a firewall that allows certain ports to pass through, and not others. Specifically, these tunnels give you various alternatives for getting to SSH on the main JTAN ProShell machine.

Service Entrance Host:Port Destination Host:Port

TELNET -> SSH webproxy.jtan.com:23 callisto.jtan.com:22

HTTP -> SSH webproxy.jtan.com:80 callisto.jtan.com:22

POP -> SSH webproxy.jtan.com:110 callisto.jtan.com:22

HTTPS -> SSH webproxy.jtan.com:443 callisto.jtan.com:22

GNU HTTP Tunnel

These ports provide "hts" server side httptunnels using Gnu HTTPtunnel. To use these, you need the "htc" client running on your PC. For more information, see the httptunnel web page.

These tunnels have 30 minute timeouts. This is to prevent people from gumming them up for long periods. If you often find that these are blocked, we would be happy to add more. Just let us know that you need more added.

Service Entrance Host:Port Destination Host:Port

HTTPTUNNEL -> SSH webproxy.jtan.com:8888 home.jtan.com:22

HTTPTUNNEL -> SSH webproxy.jtan.com:8889 home.jtan.com:22

Other Tunnelling Resources

Here are some good web pages that discuss the practice of firewall puncturing.

Firewall-Piercing

Our users have reported that some of this software is useful for tunnelling.

Corkscrew is a tool for tunneling SSH through HTTP proxies.
httptunnel creates a bidirectional virtual data connection tunnelled in HTTP requests.