I'd like to set up a series of local development servers using the same IP address and different domain names, although I'm not sure about how to set it all up.

I created the following domains server1.something.com, server2.something.com - all these domains have DNS records for the same IP address.

My question is, how can I get this to work if I have multiple machines, for example one Mac OS X machine has MAMPP installed and another Windows machine has XAMPP installed to work exactly if the single IP address is behind a router? These local development services also need to be accessed outside of the network. I'm assuming that there would need to be a combination of port changing or virtual hosts, but if someone could help me out I'd really appreciate it. 

Thanks in advance