-.It Fl C
-Requests compression of all data (including stdin, stdout, stderr, and
-data for forwarded X11 and TCP/IP connections).
-The compression algorithm is the same used by
-.Xr gzip 1 ,
-and the
-.Dq level
-can be controlled by the
-.Cm CompressionLevel
-option for protocol version 1.
-Compression is desirable on modem lines and other
-slow connections, but will only slow down things on fast networks.
-The default value can be set on a host-by-host basis in the
-configuration files; see the
-.Cm Compression
-option.
-.It Fl F Ar configfile
-Specifies an alternative per-user configuration file.
-If a configuration file is given on the command line,
-the system-wide configuration file
-.Pq Pa /etc/ssh/ssh_config
-will be ignored.
-The default for the per-user configuration file is
-.Pa $HOME/.ssh/config .
-.It Fl L Ar 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
-.Ar 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
-.Ar host
-port
-.Ar 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:
-.Ar port/host/hostport
-.It Fl R Ar 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
-.Ar 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
-.Ar host
-port
-.Ar 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:
-.Ar port/host/hostport
-.It Fl D Ar port
-Specifies a local
-.Dq dynamic
-application-level port forwarding.
-This works by allocating a socket to listen to
-.Ar port
-on the local side, and whenever a connection is made to this port, the
-connection is forwarded over the secure channel, and the application
-protocol is then used to determine where to connect to from the
-remote machine.
-Currently the SOCKS4 and SOCKS5 protocols are supported, and
-.Nm
-will act as a SOCKS server.
-Only root can forward privileged ports.
-Dynamic port forwardings can also be specified in the configuration file.
-.It Fl 1
-Forces
-.Nm
-to try protocol version 1 only.
-.It Fl 2
-Forces
-.Nm
-to try protocol version 2 only.
-.It Fl 4
-Forces
-.Nm
-to use IPv4 addresses only.
-.It Fl 6
-Forces
-.Nm
-to use IPv6 addresses only.