How to make a Loopback Cable

Sometimes in order to test a computer’s hardware or software we need a network link for the network adapter. The solution, very often, is to carry around a hub.
If you don’t want to carry around a hub, or you simply don’t have it, you can create a network loopback cable. The loopback cable will work as the computer was connected to a real network transmitting and receiving packets. This kind of setup allows the technician to troubleshoot hardware.