portfwd is a Python script which acts as a TCP port forwarder. It listens for connections on various sockets on a specified interface, and upon getting a connection, opens a socket to an external server and forwards traffic between the two sockets.
portfwd was written on a Windows NT machine to allow a VMware guest running Linux to access an external web proxy server. It is also useful for local Ethernet networks and other network types. It should, in theory, run under UNIX.
portfwd has a Tk GUI displaying a list of open connections, though this can be disabled in the script.
Before running this script, set the list of ports to be forwarded in the mappings dictionary. (Some knowledge of Python is assumed.)