CSR1000v Interface Numbering

[Daryl Clark]

We recently spun up a CSR1000v in Azure and added two interfaces to it. Unfortunately, interface Gig2 had to be moved to a different subnet and thus we had to delete the interface object, create a new one and re-add it back to the CSR. The new interface is Gig3 and we no longer have a Gig2. I want/need the replacement interface to be added back as Gig2 for consistency reasons across my datacenters.

Does anyone know how to renumber an interface on a CSR?

IOS-XE 16.12.1a

[Richard Burts]

I do not have experience with the CSR doing this. But on most other Cisco routers I would solve this by removing interface G3, saving the config, and rebooting. After reboot you should be able to create interface G2.

HTH

Rick

[Daryl Clark]

Thanks but that didn't work:

AZ-East-Hub-1(config)#no int gig 3
% Removal of physical interfaces is not permitted

[Richard Burts]

Sorry that did not work. Looks like there are syntax differences that I was not aware of. So let me backtrack a bit. You said that you delete the interface object for G2. Perhaps I should have suggested doing the same for G3 rather than trying to delete the interface. So please try removing the interface object for G3, same the config, reboot, and try to configure G2. If that does not work then please post the output of show ip interface brief, and the current running config.

HTH

Rick 

[Daryl Clark]

Thanks Rick...I was also probably not clear on that. I deleted the interface object on the Azure side, which automatically removes the interface in the CSR. When I added a new interface back it came in as Gi3...I'm thinking the fix is down inside the kernel and not something in CLI.

[dr_9356]

Apologies for this being added so late, but I came across this same issue and this thread which didn't have any solid solution. Basically I removed an interface in my hypervisor (gig4 in my case) and then when I re-added a new NIC adapter, it would only create gig5.

As of Version 15.5(3)S8 to reset the numbering run the following command:

clear platform software vnic-if nvtable

This clears out the mapping that the CSR stores, and from there you can add add new interface via your hypervisor and it will start at the next available interface.

[Richard Burts]

Thanks for the update (which is only a little bit late) which appears to be very helpful. So a well deserved +5 for finding a solution.

HTH

Rick