Most places use the TIA 568-B wiring standard for ethernet. If you're making an ethernet cable, make sure both ends look like this: If you're making a flip cable (you usually don't need to do this as most of the hubs/switches we buy have a switchable uplink port) one end should look like the standard, the other should look like this: LABLE THE CABLE AS A FLIP CABLE. If you don't, it will cause all sorts of hassle and pain when you (or someone else) is trying to debug it later.