I watched the The Black Magic Of SSH video and lecturer in this video drops to SSH shell with some key-combination. How did he do that?
If you are talking about openssh, you can get a menu of ssh escapes by using the 3-key keystroke sequence
$ ~? Supported escape sequences: ~. - terminate connection ~B - send a BREAK to the remote system ~C - open a command line ~R - Request rekey (SSH protocol 2 only) ~^Z - suspend ssh ~# - list forwarded connections ~& - background ssh (when waiting for connections to terminate) ~? - this message ~~ - send the escape character by typing it twice (Note that escapes are only recognized immediately after newline.)
This shows that
<ENTER>~C will drop you to a ssh command line. From there, you can manage some port forwarding.
$ ~C ssh> ? Commands: -Lport:host:hostport Request local forward -Rport:host:hostport Request remote forward -KRhostport Cancel remote forward
Otherwise you could drop to your local shell with