Sunday, October 24, 2010

Ethernet Cable Color Code

In troubleshooting user network issues I always start off with the physical layer. About 80% of the time that is the issue with the users network the other 20% is typical caused by malware or viruses.

Since the physical layer is so important I figured I would spend some time discussing some tips and tricks that I have picked up over the years.

First gather the required tools:
  1. Ethernet Crimper
  2. Wire Stripper
And you may want some optional tools like an Ethernet cable tester or possibly a cable verifer
if you need to make sure a wire is good.

Most good Ethernet crimpers come with a built in stripper, which works fine if you are just doing a few. However if you plan on doing more than a few you are going to want a dedicated stripper. I prefer one that is spring loaded like this one.

A few other tricks to use is get a EZ-RJ45 crimp tool
and EZ-RJ45 connectors. The EZ-jacks allow for good crimps even for beginners.

Now for the actual cable making. The Ethernet pin out for the T-568B (aka straight through) cable is the most common type of cable I make. With auto sensing switches, I rarely have to make T-568A (aka cross-over) cables any longer. The actual process is easy just separate the wires as shown in the diagram below. Put them in the the actual jack and proceed to crimp them, then test. 


Easy right? Leave me a comment if I missed anything.