Why are there crossover cable diagrams/dipictions that show two different wiring formats? I always thought the first pic below was the correct way to format a crossover cable? I've never seen the way that the second picture depicts. PS, this question is not a duplicate because I am asking for a clarification on which picture more accurately represents the format of a crossover wire, it does not give any clarification or explanation on the second method...

Crossover format that I believe to be correct:

Crossover format that I believe to be correct

Crossover format that I believe to be wrong:

Crossover format that I believe to be wrong

  • 2
  • The first one is correct. I am unclear what the second one is about. – Giacomo1968 Apr 7 '18 at 4:16
  • @JakeGould Sorry, but I have to disagree with you that this is a possible duplication of ____. That one talks about how to connect two devices together. My question asks nothing of the sort. My question is asking to clarify whether the first or second picture is the correct format in which you use in the making of a crossover network cable. That other question may have an answer that could clarify/answer mine, the question does not focus close enough to the topic in which I asked. – StrangeRanger Apr 7 '18 at 4:24

Either would have worked back in the days of 10BASE-T and 100BASE-TX, because those standards only used two pairs: 1&2 and 3&6.

But 1000BASE-T and 10GBASE-T use all four pairs, so you have to cross them all over like in the second image if you want gigabit and 10G to work.

So the one you thought was wrong was a little more right than the one you thought was right.

  • Would you still recommend using the wiring format depicted in the second picture even if I don't plan on using gigabit and 10G? – StrangeRanger Apr 7 '18 at 4:47
  • If your 1000BASE-T (and 10GBASE-T) equipment is new enough to have Auto-MDI/MDIX, then the half-right crossover cable could be okay (but not even necessary). "Not planing on using Gigabit" is shortsighted. – sawdust Apr 7 '18 at 7:59
  • But it wouldn’t hurt to use the second picture, right? – StrangeRanger Apr 10 '18 at 16:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.