NetworkTransport : Cannot open socket on ip {*} and port {25000}

I'm getting the following error "Cannot open socket on ip {*} and port {25000}; check please your network, most probably port has been already occupied" on my PC when testing the server AND client on one machine (the Linux machine needs to be reformatted that's why I'm only using one PC now) and am wondering if it's possible to allow multiple games to use one socket/port in Unity's NetworkTransport...

The code I've used it pretty basic from what the documentation shows and so far I'm...

NetworkTransport : Cannot open socket on ip {*} and port {25000}