I want to add a crossover to my network toolbox. Aside from an actual an actual crossover cable, I like the idea of an adapter (figure 1). There are crossover adapters available online, but I’m wondering about making one out of an Ethernet coupler (figure 2).
There are plenty of pages that show wiring diagrams for crossover cables, but it’s pretty confusing because there are several different wiring schemes depicted. Further, while it should only be needed with two 10/100 NICs, I want to make sure it doesn’t cause trouble if one or both of the NICs are GbE (I’m worried about damaging a NIC if the wires are not connected correctly).
Can anybody tell me whether there are any caveats about making a crossover from a coupler instead of a cable and which wires should be crossed?
Figure 1: Crossover adapter
Figure 2: Ethernet coupler
Best Answer
There are no caveats to doing this with 10/100 NICs. Most people would use 568B on one end, and 568A on the other, on a Cat5(e)/6 cable.
You seem to not be most people. You need to just make sure that these pins have continuity across the coupler:
1 <-> 3
2 <-> 6
3 <-> 1
6 <-> 2