If you're running timing tests, in all probability what someone wants is to gather statistics on how long it takes to load the pages from different computers. But they might not understand enough about networking to further qualify their request to mean computer located in different places on the internet, reaching the website through different paths.

Gathering statistics from one computer that's pretending to be several is rather like asking the same person to take a survey three times.

You may need to have a talk with whoever is asking you to run this experiment, to explain to them a bit about how networks work, and to help them clarify what they're trying to measure.

Once the machine is configured with multiple IP addresses per your needs, make use of the bind function before you make your outbound connect (this can be done with IO::Socket just as easily using the LocalAddr variable). This ensures the outbound connection comes from the IP address (and port, if you want that level of control) that you want.