SSH: tunnel without shell on ssh server

As said in other posts, if you don't want a prompt on the remote host, you must use the -N option of SSH. But this just keeps SSH running without having a prompt, and the shell busy.

You just need to put the SSH'ing as a background task with the & sign :

ssh -N -L 8080:ww.xx.yy.zz:80 user@server &

This will launch the ssh tunnelling in the background. But some messages may appear, especially when you try to connect to a non-listening port (if you server apache is not launched). To avoid these messages to spawn in your shell while doing other stuff, you may redirect STDOUT/STDERR to the big void :

ssh -N -L 8080:ww.xx.yy.zz:80 user@server >/dev/null 2>&1 & 

Have fun with SSH.

-f -N is what you are looking for:

ssh -f -N -L MY_LOCAL_PORT:FOREIGN_ADDRESS:FOREIGN_PORT MYUSER@SSH_SERVER

From the ssh man page:

-f Requests ssh to go to background just before command execution. This is useful if ssh is going to ask for passwords or passphrases, but the user wants it in the background. This implies -n.

-N Do not execute a remote command. This is useful for just forwarding ports (protocol version 2 only).

-n Redirects stdin from /dev/null (actually, prevents reading from stdin). This must be used when ssh is run in the background.