Cisco Console to Null Modem Serial Adapter

Currently, I am lugging around my USB to Serial cable (since my laptop does not have a serial port), a Cisco console cable, and a null modem cable (for older switches and other equipment). When I work on older equipment, I have to unplug my Cisco console cable, find my null modem cable, and then plug all of that in.

Wouldn't it be easier if I had an adapter that I could carry around instead of switching cables? Or better yet; maybe I could make a bunch of these cables and keep them plugged into what few older switches we have left.

I know there are probably adapters out there already, but I did not want to purchase anything. I figured making one would be easy enough. Especially since I had about a billion console cables in a box from all the Cisco stuff we ordered (better to reuse than hitting the trash can). So I grabbed the parts and headed to my workbench.

Step 1 Parts and tools needed

PARTS NEEDED:

QTY: DESC:
2 Cisco Console Cables
1 RJ45 Network Jack


TOOLS NEEDED:

Scissors, knife, or cable cutters (or all three... the shielding is tough!)
Needlenose Plyers
Punch down tool (unless you have an RJ45 that does not require a special tool)
(OPTIONAL) Multimeter to test the pinouts

Comments

[un1golan]

I do not believe in cutting cables. You can simply create Null Modem cable over the network by connecting the sockets you use from the parch panel with a so called "roll-over" Ethernet cable. That is a 1-8 pins go to 8-1. It may be harder to find to buy one than make one at home with a cramping tool. So putting head to head: Cisco Console cable - Ethernet "roll-over" cable - Cisco Console cable you create a Null Modem cable. :) You're Welcome!

[Creepy Kid]

I am uncertain on how to read this chart. Is the Orange on the Cisco cable the RJ-45 equivalent of Blue, because thats immediately to the right, or the RJ-45 equivalent to Orange-White, because they share the same number?

[cowen]

Simple you read the chart the way the cable was crimped. Do not mind the color in the cable the position of the color is the important part. Every Jack uses the 568a/b standard the author chose the 568B pin out to use. To actually color code this to a jack would assume that CISCO uses the same colors all the time. This would be a 90% true statement. Looking at the crimp end with the gold pins facing you record the colors and what pin that color goes to should follow the above chart then you need to match that position to the correct position on the CAT5 jack using a 568B configuration as the chart shows above. I build these cables daily you just need to record and know that the jack has to match the end you cut off. The author also put the correct null modem swaps of hand shacking into the cable on the re build. pin 7 never got to pin 1 in a network cable. you just need to not think about 568a/b cable standards here and what does it take to connect and switch handshaking and data flow for RS232.

[Jestersage]

BTW, on that table, is that the wiring for the rollover cable, or the wiring for the new nullmodem cable?

[GorillazMiko]

Nice job, done very neatly. What is cisco again? It's a program that lets you chat or something.. right? I forgot. :P

[jwilson27]

Thanks!
Sorry, but my sarcasm detector has never been that great. Just in case people want to know, Cisco is mostly switches and router devices. I recommend using them whenever possible. I have not found a competitor yet that can match Cisco's hardware, software, and support.

Check them out at Cisco.com

And no, I do not work for nor do I get paid to endorse Cisco in any way. They just make great stuff and I will always give praise where praise is due.

[NarNar]

What are these cables used for, anyways?
No sarcasm intended.™

[GorillazMiko]

Are you saying I was trying to be sarcastic?
Because I wasn't.

_:P

[jwilson27]

No, I did not mean to accuse anyone. I was just saying that I cannot detect sarcasm. Everything is cool and I appreciate the question. Thanks man!