-L port:host:hostport
Specifies that the given port on the local (client) host is to be forwarded to the given host and port on the remote side.
This works by allocating a socket to listen to port on the local side, and whenever a connection is made to this port, the connection is forwarded over
the secure channel, and a connection is made to host port hostport from the remote machine. Port forwardings can also be specified in the
configuration file. Only root can forward privileged ports. IPv6 addresses can be specified with an alternative syntax: port/host/hostport.
-R port:host:hostport
Specifies that the given port on the remote (server) host is to be forwarded to the given host and port on the local side.
This works by allocating a socket to listen to port on the remote side, and whenever a connection is made to this port, the connection is forwarded over
the secure channel, and a connection is made to host port hostport from the local machine. Port forwardings can also be specified in the
configuration file. Privileged ports can be forwarded only when logging in as root on the remote machine.
IPv6 addresses can be specified with an alternative syntax: port/host/hostport.
