Ethernet Crossover Cable
An Ethernet crossover cable is a type of Ethernet cable used to connect computing devices together directly where they would normally be connected via a network switch, hub or router. For example, one would use a crossover cable to directly connect two personal computers via their network adapters.
Ethernet Crossover Cable Pinout
Making an ethernet crossover cable is not difficult if you know the proper pinouts and have the proper tools and materials. See photos below for 100Mbps and Gigabit crossover cable pinouts.
100Mbps Crossover – 10baseT/100baseTX crossover ( shown as T568A )
Gigabit Crossover – 10base-T/100base-TX/1000base-TX/T4 crossover (shown as T568B)
In practice, it does not matter if your Ethernet cables are wired as T568A or T568B, just so long as both ends follow the same wiring format. It is just as valid to make a four-pair crossover using T568A, or a two pair crossover using T568B, as it is to wire them the way shown here.
Typical commercially available “pre-wired” cables can follow either format depending on who made them. What this means is that you may discover that one manufacturer’s cables are wired one way and another’s the other way, yet both are “correct” and will work. In either case, T568A or T568B, a normal (un-crossed) cable will have both ends wired according to the layout in the first connections column.