Gnome has a handy utility for managing your SSH tunnels called gSTM (Gnome SSH Tunnel Manager). But if you have to manage a large number of tunnels, the GUI becomes quite painful. Instead, you can edit the configuration files by hand. The files are stored under $HOME/.gSTM.
$ ls -l ~/.gSTM
-rw-rw-r– 1 chandru chandru 1354 Sep 3 04:50 jumpbox1.reJBkD.gstm
-rw-rw-r– 1 chandru chandru 2901 Sep 5 09:51 jumpbox2.0VZHUf.gstm
-rw-rw-r– 1 chandru chandru 1212 Aug 31 14:51 jumpbox3.Fg3FFh.gstm
A sample entry in one of the configuration file looks like this.