An Ethernet crossover cable can be used to directly connect two network devices through Ethernet. These can either be single computers or they can be networks. Ethernet crossover cables are commonly used for temporarily networking two devices in the absence of a network router switch, or hub. The principle is the same, but the connection speeds and methods are different. The crossover cable’s function is to send and receive data. Ethernet crossover cables enable complex data transfers between computers, routers, and networks.
Unlike standard ethernet, the internal wiring of Ethernet crossover cables reverses
the incoming and outgoing signals. The reversed wires are color coded and can be observed inside the RJ-45 connectors at each end of the cable. Standard cables have an identical sequence of colored wires on each end, while crossover cables have the 1st and 3rd and 2nd and 6th wires crossed. Note that a crossover cable differs from the usual Ethernet cable as the crossover cable allows data to be sent and received on both ends, whereas the usual Ethernet cable allows only one-way data transfers.
NOTE: Crossover cables should only be used for direct network connections while connecting devices of the same type.
Ethernet Crossover Cable Pinout
| Name | Color on NIC1 | NIC1 | NIC2 | |
|---|---|---|---|---|
| TX+ | White/Orange | 1 | 3 | |
| TX- | Orange | 2 | 6 | |
| RX+ | White/Green | 3 | 1 | |
| – | Blue | 4 | 7 | |
| – | White/Blue | 5 | 8 | |
| RX- | Green | 6 | 2 | |
| – | White/Brown | 7 | 4 | |
| – | Brown | 8 | 5 |
