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FR home lab question


I'm studying for my CCNP (passed the switch exam) and I'm using GNS3 for the route exam which can cause me headaches with the idelpc option from time.  Anyway I also have some routers sitting there doing nothing that work gave me for my studies, but I'm finding I don't need them due to GNS3, but feel it's a waste.  Did you use real kit for your studies?

I have:

2 x 2620s

1 x 2621

2 x1841s

It would be useful to use 1 router as a FR switch so should I buy a NM-8A/S 8-port Serial Module giving me 8 serial ports and use it in a 2620 or I see you can buy a Cisco 2520 FR switch for a tiny bit more giving my 5 serial ports.

Or should I save my money and just use GNS3?



Re: FR home lab question


It's more of a personal choice whether to use GNS3 or real gear, the end result would still be the same. Personally, I took the GNS3 route due to budget constraints.

If you choose to use GNS3, make sure your PC has good specs or plenty of RAM. I've read a lot of folks can pass ROUTE mainly using GNS3.

Alternatively, you could use a 2522 for your FR switch. It has an 8 built-in serial ports. You could then sell it once your done with ROUTE or use it for CCIE R/S if you plan to upgrade your skills.

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Cisco Employee

Re: FR home lab question

Hi Andrew,

John has given some very good advice here. I personally use a 2522 as the frame-relay 'cloud' in my home lab and it works like a charm. Its perfect for studies all the way up to the CCIE exam.



Cisco Employee

FR home lab question


To add to great answers by John and Aninda, I do admit I use Dynamips/Dynagen all the time (and may God bless the guy who wrote it - anyone irked at the related licensing issues please contact me via private message to discuss this privately ). I have not been using GNS3, though. I know it is much more flexible and convenient than writing topology scripts for Dynagen. At the same time, GNS3 does not seem to be as stable as Dynamips/Dynagen combination and for some inexplicable reason, GNS3 has always been more heavy on my CPU than Dynamips/Dynagen combination. Using Dynamips/Dynagen with recent 2691 images has always worked like a charm for me - very stable, feature-rich, relatively low CPU, and regarding the idlepc value, once you get a good value for a particular image, there is no need to re-evaluate it.

So I would personally suggest learning how to use the Dynagen, and stick with it, even if it is less convenient than the GUI-driven GNS3.

Best regards,


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