System Downtime

February 1, 2009

Tunneling a connection through SSH

Filed under: Dorm Life, Linux — Tags: , , , — Michael Pobega @ 2:23 PM

So I finally arrived at school, only to find that my college has decided to block IRC on the campus wifi. Weirdly enough, they allow AIM/MSN/Jabber/Skype/Ekiga/etc traffic, but not IRC. According to the IT department “IRC is commonly used to spread viruses”. I’m not sure how valid that is, but it didn’t stop me from trying to connect to my usual IRC networks.

Luckily all they did was block the common (6000~7000) IRC ports, which meant that I could still get on any networks that offered alternate ports. But for those odd servers that don’t offer any ports outside of the 6000~7000 range, there is another way to get around this block using an SSH tunnel and a program called tsocks, a program made to simplify the use of a SOCKS proxy connection. After installing tsocks find tsocks.conf and make sure everything else is commented out but:

server = 127.0.0.1
# Server type defaults to 4 so we need to specify it as 5 for this one
server_type = 5
# The port defaults to 1080 but I’ve stated it here for clarity
server_port = 1025

Now when you connect to your SSH server, you use the -D flag followed by the port in your tsocks.conf. For example, if you were using my configuration you would run ssh -D 1025 servername

Another use for this is to achieve wired connection speeds with a wireless connection – you can tunnel wget through tsocks and increase your download speed (considering your SSH server is on the local network)

Have fun and happy chatting!

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