Piercing a firewall with SSH

SSH allows tunnelling remote services through an SSH connection:

• This allows accessing all services in a machine by opening a single port.
• It requires an account in the remote machine.

Tunneling a remote service to the local host:

$ ssh -L PORT:HOST:HOSTPORT [USER@]HOST

Tunneling a local service to a remote host:

$ ssh -R PORT:HOST:HOSTPORT [USER@]HOST

• Activity