How do I make a crossover cable from scratch on a RJ-45?

[Dewy]

How do I make a crossover cable from scratch on a RJ-45? please provide details, thanks in advance.

 

[Bobg1]

Terminate one end the standard way, on the other end swap pairs 2 and 3. If your not familier with the pairs that would be pins 1,2 and 3,6.
1 > 3
2 > 6
3 > 1
6 > 2

 

[jimbopalmer]

traditionally pins 4,5,7, and 8 still go straight through.

I tried to remain child-like, all I acheived was childish.

 

[DTSMAN]

If you are running a cable and terminating the ends with jacks just punch one down A version and the other end B version. Then just use standard patch cables.

 

[smah]

Here's a more visual version:

http://www.duxcw.com/digest/Howto/network/cable/cable5.htm

 

[daronwilson]

Again folks, it might be a good time to start doing a full crossover cable just by habit. If you want your crossover cable to be capable of gigabit ethernet as well, you need to swap the other two pairs too. I've only run into the problem in data closets where there are gigabit switch uplinks, but it's probably worth doing for the future.

Good Luck!

It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[jimbopalmer]

Daron can I play devil's advocate?

Most of the 1000bastT chipsets I work with (macs) auto detect MDI and MDIX so at gig I do not need crossovers as often

on the other hand, I use a fair number over wireless access points so I DO need Power Over Ethernet.

As such, I am still building them with 4,5,7, and 8 straight through for POE and hoping that Gig E adopts the no cross over needed chips!

I tried to remain child-like, all I acheived was childish.

 

[daronwilson]

Well yes, that makes sense. I just had to build two of them for Cisco switches with gigabit uplink modules. I confess I was just asked to do it, so I didn't see if they would auto detect. Point well taken, thanks!


It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[jacassc]

One little additional tip. Please mark both ends of the cross over cord [ x/o ] on both ends. You never know that cord will cause in the future. LOL