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I am giving up on CML. Going back to VIRL


I have been using

  • VIRL for a few years
  • virtual images on ESxi for 5 years
  • GNS on and off for 15 years
  • physical hardware for 25 years


my thoughts and feedback of CML

  1. There doesn't appear to be much support for the product.  the community is trying to help each other
  2. the supplied OVA is not compatible with VMware 6.5.  One of my VMware guys fixed it for me
  3. there is no documentation for CML install on ESXi
  4. the CML CSR1v image won’t accept tagged frames.  This is very basic functionality that should have been tested
  5. the console ports stop working at times
  6. i have a 20 node license, but can't have more than 4 IOS-XR, 8 CSR1000v routers and one unmanaged switch without receiving an error that i have exceeded my node count
  7. i restarted CML via the sysadmin page.  I have not regained access since.  i have tried restarting the CML virtual machine via vSphere to no success.  i reach the console of CML, but am unable to ping the CML address from a device on the same subnet.  I have tried running the initial ipconfig python script, but it now fails.  This was originally successful.  I will likely have to re-install.  Not sure what kind of licensing issues that will bring me
  8. running the solution to use an external terminal editor is odd.  i have had to run this tool on all computers that have access to my CML.  
  9. I personally don't think CML is ready for production
  10. i haven't even tried to build real toplogies yet.  this will be the true test
  11. i will try it again in a few months, when the kinks are ironed out

Would love to hear from Cisco on my experience


on the positive side

It doesn't seem to require nearly as much CPU and RAM as VIRL

It's a pretty design.  I like not having to use maestro





@cslefort wrote:


on the positive side

It doesn't seem to require nearly as much CPU and RAM as VIRL


Do you have any stats to share?

My biggest concern is the CPU and RAM requirements .. for these images.

I can run appr. 40 IOU nodes in Eve-NG with 8 GB RAM 4 Core CPU.

Would love to see if Cisco can give us something similar .. I would like to use CML due to API support compared to Eve-NG. But CPU and RAM requirements are a downer for me.


Thanks for sharing your feedback. 

I shutdown my CML, so can’t check


virl was running 4 xrv9k and 14 csr1000v.  Was chewing 20 cpu and about 150gigs of ram

The xrv9k are hogs


cml was a small fraction of virl




So buggy at even a basic level.....I prefer packet tracer over this hot mess!  Good luck finding any support, as cisco sends you in a web loop when searching for it.

and this is the 3rd different official cisco forum for cml that I have come across today


Rebooted CML again.

had to license again

i can now deploy 20 nodes

consoles appear to be working for all devices via breakout

I think I too am giving up on CML.  I spent 2 weeks in license h3ll, then after all that got straightened out, I started getting Not Ready Errors.  Go in and reset the whole thing back to defaults, worked for a couple of hours, then right back to Not Ready Errors.


Downloaded new VM and ISO, allocated 6 cores (on an I7) gave it 26gigs of RAM and expanded the hard drive to 32gigs....and the same error is happening on both VMs.


I think there are other options that are better than CML at better price points.  $199 is a bit pricey for a piece of software that is this unreliable.  I think it is a good idea, but, not yet ready for prime time.

Stephen Craven
Do you recall anything about how the VMWare guy fixed your OVA for 6.5?

I feel your pain...


"the CML CSR1v image won’t accept tagged frames.  This is very basic functionality that should have been tested"
Thanks for mentioning this, I was trying to find out why nothing seemed to work with these images. This is so stupid, why is this working with the small IOSv images but not with the CSR1ks?

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