‘When you are forwarding ports through a tunnel, either locally or remotely (i.e., with the -L or -R switches), you can modify the session real-time. The way that you do this is after you start the session, you press SHIFT + ` + c (The ` key also has a ~ in it, which is the actual keypress sent to the session). If it doesn’t work the first time, press ENTER a couple of times and try it again. Once you get the “ssh>” prompt, type “?” for the commands you can put in. Here’s an example session:

[0908][scott@dev:~]$ ssh -R 8080:suseblog.com:8080 scott@suseblog.com
Password:
Last login: Thu Oct 15 11:59:43 2009 from 67.214.232.162
Have a lot of fun…
[1109][scott@mail:~]$ [PRESS SHIFT + ` + c HERE]
ssh> ?
Commands:
-L[bind_address:]port:host:hostport Request local forward
-R[bind_address:]port:host:hostport Request remote forward
-KR[bind_address:]port Cancel remote forward
[PRESS ENTER HERE]
[1110][scott@mail:~]$ [PRESS SHIFT + ` + c HERE]
ssh> -R8080:letslearnlinux.com:1080
Forwarding port.

[1110][scott@mail:~]$’