ssl:ip:port

The specified SSL port on the host at the given ip, which must be expressed as an IP address (not a DNS name) in IPv4 or IPv6 address format. If ip is an IPv6 address, then wrap ip with square brackets, e.g.: ssl:[::1]:6640. The --private-key, --certificate, and --ca-cert options are mandatory when this form is used.

tcp:ip:port

Connect to the given TCP port on ip, where ip can be an IPv4 or IPv6 address. If ip is an IPv6 address, then wrap ip with square brackets, e.g.: tcp:[::1]:6640.

unix:file

On POSIX, connect to the Unix domain server socket named file.

On Windows, connect to a local named pipe that is represented by a file created in the path file to mimic the behavior of a Unix domain socket.