I have just taken delivery of a basic Cisco lab and I would like to check the routers and switches etc. are in 'working' condition before I start playing around with them.

The first hurdle is probably the most obvious - I don't know how to get console access to actually do anything on the hardware!

The first in the list is a Cisco 2516 - you can see the ports available on the following table (taken from this website:


Here is a list of the contents of the lab (provided to show you what cables I have access to):

lab contents

I also have a serial to USB cable that I had before the lab arrived.

So far I have tried to connect to the RJ45 console port on the Cisco 2516, to the RJ45 port on my laptop. It would appear from everything I have read online that you have to connect to either serial or USB on the laptop - is this correct?

If so, do I need two adapters? One thats RJ45 to USB and another thats DCE/DTE to USB?

I notice that none of the equipment has the RS-232 serial connection that I expected!


The console port on the 2516 is indeed a serial port, but it uses an RJ45 connector and a weird "rollover cable" to connect the RJ45 console port on the hub to the serial port on your laptop. You should have got a rollover cable with the hub; last time I bought any Cisco kit, they were light blue thin ribbon-style cables with a standard 9-pin serial connector on one end and an RJ45 connector on the other. They're called rollover cables because the pins at either end are wired 1->8, 2->7, 3->6, etc.

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  • @Chopper3: thanks for the edit! I didn't realise you could just include the image like that. – RainyRat Aug 31 '11 at 13:07
  • Great thanks! The above cable went into the serial to USB and it all worked. Thanks again! – dannymcc Aug 31 '11 at 13:09
  • It's not the most intuitive connector scheme, is it? Happy to help. – RainyRat Aug 31 '11 at 13:11
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    Actually they don't still do that. The latest routers from Cisco now have the old RJ45 console as well as a 5pin mini-USB console which works as a USB->Serial converter (Cisco provides a driver that keeps the port number assigned so the USB console always comes up as the same COM port for your terminal software to use). So a standard mini-usb cable can be your console cable on those routers. – Thomas G Aug 31 '11 at 14:09
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    This type of cable makes a lot of sense in Data Centres with structured cabling as you can use the existing RJ45 patch panels to carry the console data and have a central console server such as an Avocent Cycades. – Niall Donegan Sep 7 '11 at 15:23

Each piece of equipment equipped with a console port should include a baby blue colored rollover cable. This flat cable should have a DB-9 on one end and a RJ-45 on the opposite end. The DB-9 should plug right into your USB-to-serial converter.

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