A crossover cable directly connects two network devices of the same type to each other over Ethernet. Ethernet crossover cables are commonly used when temporarily networking two devices in situations where a network router, switch or hub is not present.

Compared to standard Ethernet cables, the internal wiring of Ethernet crossover cables reverses the transmit and receive signals. The reversed color-coded wires can be seen through the RJ-45 connectors at each end of the cable:

• Standard cables have an idential sequence of colored wires on each end
• Crossover cables have the 1st and 3rd wires (counting from left to right) crossed, and the 2nd and 6th wires crossed