What kind of port are you talking about? I was recently in Portugal, in the city of Porto and at the river (near the port), they served interesting wine, called portwine.

But even if we restrict the discussion of ports to a computer, there are at least three ports commonly used that spring to mind:

• The serial port, also known as RS-232 or RS-432 (hardware).
• The parallel port, also known as IEEE 1294 (hardware).
• The TCP/UDP port number of a TCP or UDP listening socket (software).

If you are talking hardware, I would suggest a hardware solution. Either plug in the test system into a different port of the computer, or splice the cable to connect to two machines.

If you are talking software, there are various ways of doing what you're interested in, at least if I understand what you are actually interested in.

I interpret your statements in the software sense as having some software that expects to talk TCP/IP on a fixed port number. You want to make two (or more) instances of that software coexist on the same machine, preferrably on the same network adapter.

If you cannot change the port number (the easiest way), you can maybe use your operating systems facilities. The *BSD family of operating systems has convenient port redirection facilities (even available as Perl module). If you cannot do this redirection (transparently) within your OS, you might want to look if you can run your local program via inetd which can launch a new process for every incoming connection.

If that solution does not seem what you want, maybe you can specify what you want more clearly in terms of a comparison to POE, or Apache, or HTTP::Proxy, or even netcat.

Thanks to calin for spotting various typos.

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