An Ethernet crossover cable, also called a crossover cable, connects two Ethernet network devices. These cables support temporary host-to-host networking in situations where an intervening device, such as a network router, is not present. Crossover cables look almost identical to regular, straight-through (or patch) Ethernet cables, but their internal wiring structures are different.
Network Basics – Straight-Through vs. Crossover Cables
A regular patch cable connects different types of devices, such as a computer and a network switch. A crossover cable connects two devices of the same type. You can wire the ends of a patch cable in any way you like, as long as both ends are identical. Compared to straight-through Ethernet cables, the internal wiring of a crossover cable reverses the transmit and receive signals.
You can see the reverse color-coded wires through the RJ-45 connectors on both ends of the cable:
A good Ethernet crossover cable will have special markings that distinguish it from straight-through cables. Many are red and have "crossover" stamped on the packaging and the cable jacket.
