Using netlab to Argue with Vendor TAC
A happy netlab user sent me an unexpected use case: they successfully used its multi-vendor capabilities to argue with a vendor TAC. Here’s the gist of the story (edited/anonymized for obvious reasons):
So far so good. These things happen. Unfortunately, the next step turned out to be a TAC hell loop.
They were probably also asked to upgrade the software and reload the boxes 🤦♂️. I’ve been in similar situations several times, but in those days, we didn’t have virtual network devices. Now we do ;)
They subsequently recreated the physical topology in a netlab lab with the minimum of devices. Their setup was simple enough that they could use the standard netlab functionality to recreate the bug, and as expected, Arista cEOS and FRR didn’t cause an outage. Grumpily (so the user), they jumped through the hoops to netlab-up with vendor devices. Lo and behold, the outage could be reproduced.
Instead of continuing the never-ending TAC discussions, they sent the vendor TAC team the netlab topology file and asked them to reproduce the issue on their own.
Note: jumping through the hoops was caused by netlab failing to install libvirt on a Ubuntu 25.04 VM with nested virtualization. The root cause might have been the netlab installation script (now fixed) that was never tested on Ubuntu versions newer than 24.04.
Anyway, two weeks later, I received a wonderful follow-up message:
Have you used netlab in an interesting or unexpected way? Please let me know.
It can only be the American company beginning with C.
It was an American company, but a different first letter (not that I would expect anything different from any of the large conglomerates).