SSH Tunneling isn't new to the show, we've done it before over DNS or in conjunction with VNC. Today we're looking at two SSH tricks for tunneling just about any traffic.

First up, ssh -D. The -D option specified a local "e;Dynamic"e; application-level port forwarding. Any connection made to the specified port goes through the tunnel as a SOCKS4 or SOCKS5 proxy. Perfect for secure web browsing as demonstrated with Firefox in this segment.

ssh -D 8080 user@server

Second, ssh -L. The -L option enables port forwarding. Using this option tells the SSH client to listen to traffic on a specified port and forward it along through the tunnel. The server receives this data and points it to the specified destination, whether it be on the destination network or otherwise. In our example we use the -L option to securely connect to an open IRC server.

ssh user@server -L local-listen-port:destination-ip:destination-port

For more SSH-fu check out the ssh man page or Linux Journal's interesting series on 101 uses of openssh.