Options for Connecting a Console Cable

I've experienced these scenarios that I discuss in this post, and have found the mentioned parts/tools come in very handy during such scenarios.

First, below is a picture of the usual console cable and serial adapter I have in my bag.  It is a Cisco rollover cable, with an RJ45 network connector on one end, and a DB9 serial connector on the other end.  Then I connect a serial to USB adapter to the blue rollover (console) cable to connect it to my newer laptop, which does not have a serial port.

                                  

However, there have been at least two situations where I needed (and happened to have or find) a different style of console cable.  This kind of rollover has an RJ45 connector at both ends, rather than a serial connector.

Console aka Rollover Cable with RJ45 connectors are both ends

I also have an RJ45 to DB9 adapter to connect the dual-RJ45-ended console cable to my serial to USB adapter.

RJ45 to DB9 adapter

So, one situation was where I needed the console cable to be really long because I'm consoled onto an AP on the top of a pole or something, and didn't want to troubleshoot standing with my laptop on top of a tall ladder or lift.  So, here's another handy tool I used - a straight thru Cat6 coupler.

Cat6 Coupler

The trick is, connect the coupler directly to the second RJ45 end of the console cable, then connect a long regular straight through Ethernet cable to the other side of the coupler, then put the RJ45 to DB9 adapter on the end of the Ethernet cable and attach your serial to USB adapter.

Example of how to utilize a Cat6 coupler

Since the coupler is a straight through, and the Ethernet is a straight through, it effectively extends the rollover cable directly to your computer.



Another way to use this method, which I've experienced as well, is if you are working in one end of the building (like your warm office) and need to console onto a piece of gear in the very cold Data Center, at another point of the building.  Yes, this is a lazy person scenario!

Here's what to do -

1)  Find the corresponding switchport to the network jack in your office wall (hopefully you have at least two working wall jacks so you can console onto the gear via one, and utilize a wired network connection via the other).

2) Take your dual-RJ45-ended console cable to the Data Center, and connect the previously located switchport to the corresponding patch panel port.

3)  Go back to your office with the wall jacks, and connect a regular Ethernet cable to the wall jack that corresponds to the patch panel port you just plugged the console cable into in the Data Center.

4)  Attach the RJ45-DB9 adapter to the end of that Ethernet cable

5)  Finally, connect the Serial to USB adapter to the serial port on the adapter on the end of the Ethernet cable


Again, this effectively extends the console connection from the gear in the loud, cold Data Center to the quiet, comfy, cozy office.



I have also found Cat6 couplers to come in handy when I needed to stretch an Ethernet cable across a warehouse to test a troublesome single port connection.  I did not have a cable long enough, but I had about 5 couplers and a bunch of 5 to 7 ft Ethernet cables.  So I daisy chained them all and stretched it across the empty warehouse (after verifying the daisy chained cable worked itself, of course).


Lastly, at one point we needed a crossover cable to creatively console onto a ClickShare device or something; we didn't have any crossover cables around, but I happened to have two Cat6 crossover adapters in my bag, which with just one we converted a regular straight through cable into a crossover cable.  So we were able to save the day as usual.

Crossover Adapter

Hope this helps somebody else!