Nowadays, I usually make EIA/TIA-568A crossover cables for Fast Ethernet(10/100 Mbps) networks. On these cables, just 2 of the 4 wire pairs are used to comunications(the 2 remaining could be used for PoE or just for nothing), so I just needed to cross 2 color pairs(1-2 and 3-6 wires). However, on Gigabit Ethernet all the 4 wire pairs are used to increase the network bandwidth. So, to do a crossover on a Gigabit Ethernet I would need to cross all the 4 pairs. Is this feasible and reliable? I mean, how to make that and what is the correct color order of both ends of a Gigabit Ethernet crossover cable?

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5 Answers

Wikipedia has pinouts for a gigabit crossover cable.

Note that while Auto-MDIX is an optional feature of the gigabit ethernet specification (IEEE 802.3-2008: "Implementation of an automatic MDI/MDI-X configuration is optional for 1000BASE-T devices"), most gigabit ethernet interfaces do implement it, so in most cases you will not need a special crossover cable.

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You don't: Auto MDI-X is built into the Gigabit Ethernet spec. The endpoints will auto-negotiate and take care of those communication issues.

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For gigabit this is the pin layout you want to follow

PIN 1 - PIN 3 PIN 2 - PIN 6 PIN 3 - PIN 1 PIN 6 - PIN 2

So far this is a regular crossover cable. for gigabit use

PIN 4 - PIN 7 PIN 5 - PIN 8 PIN 7 - PIN 4 PIN 8 - PIN 5

For a color graphic guide follow the link below, is basically

ORANGE/WHITE ORANGE GREEN/WHITE BROWN/WHITE BROWN GREEN BLUE BLUE/WHITE

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Your observation is correct. The solids always go to the solids, and the white stripe to the white stripe. The drawing is incorrect. The Tyco Products PDF instruction sheet is the correct way. See

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Concerning a four pair crossover cable, for pairs on pins 1/2, 3/6, 7/8, the lower number pin is tip and the higher is ring (not to be confused with Transmit and Receive). However, in the 5/4 pair, 5 is tip and 4 is ring. This is indicated by the white stripe of each pair. Can anyone explain how 5 tip can crossover to 8 ring? The polarity of 7/8 would be reversed.

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