SSH

1. #ssh $USER@$HOST
(Run command on $HOST as $USER (default command=shell))

2. #ssh -f -Y $USER@$HOSTNAME xeyes
(Run GUI command on $HOSTNAME as $USER)

3. #scp -p -r $USER@$HOST: file dir/
(Copy with permissions to $USER's home directory on $HOST)

4. #ssh -g -L 8080:localhost:80 root@$HOST
(Forward connections to $HOSTNAME:8080 out to $HOST:80)

5. #ssh -R 1434:imap:143 root@$HOST
Forward connections from $HOST:1434 in to imap:143)