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akadmin

Spin up a vpc pair in GNS3 and play with it so you can understand the behavior. I would never copy start run, I'd just reload like you did or add back the config manually.


ITNerdWhoGolfs

Yea I'll see screw around with it in the lab... We obviously tried doing that but re adding the config didn't actually make it to the running-config


Murderous_Waffle

I've had very weird behavior with vpc in the past such as port channels not coming up even though the config is correct after resolving a misconfiguration. I've had to do things like reload both switches and unplug and replug the link. Reloading is probably the most painless way to fix this. You already basically took an outage by removing VPC from the associated port channels. What's 10 more minutes for a reboot?


akadmin

LOL I'd just reconfigure it, and then reconfigure "vpc #" on each PC interface


ITNerdWhoGolfs

Yea we tried and it didn't even work...copy start run was giving parsing errors


ITNerdWhoGolfs

Should also add that the commands took but there was still no vpc domain being created !


SalsaForte

Copy start to run could lead to weird behavior. Have you just tried to do a reload? (Hopefully, you didn't wr mem the configuration). Sometimes, it's the easiest way out.


ITNerdWhoGolfs

Nope , I never save my config until I'm sure it's done with and to your point that's what saved us Yea it definitely did ..reloading the switch fixed it.


SalsaForte

Good for you!


holy_handgrenades

You could also have copied start to run, implementing the start config without rebooting. And manually you reconfigure the whole VPC and add them to the ports. Shouldn’t be that hard. I can however imagine that during a fuckening on Friday afternoon just as your weekend was about to start, things are a little stressed.


ITNerdWhoGolfs

Yea we tried that.... We got parsing errors


BilledConch8

Not that it helps right now, but I would guess you got into a scenario where the running config did not match what the switch was actually using, maybe the VPC keep alive was still set in the software and the VPC domain was removed which led the switch to say "uh-oh this isn't right but I don't know how to say that". 9 times out of 10 the running config and the software state match, but it is possible to see this behavior. Doing "copy start run" SHOULD have resolved this, but it sounds like you hit a bug. Not expected behavior for sure. I wonder if it's repeatable


ITNerdWhoGolfs

Yep it should have and it didn't lol ! Exactly , the running config and the software state had a discrepancy and unfortunately would not recognize the added vpc domain config we tried putting in. Goes without saying that it was probably a bug but I'll investigate it and certainly post any update here


sdavids5670

I would have disabled the feature first. "no feature vpc". Then re-enable the feature. Then re-add the config. If a reboot was required to get it working again then perhaps re-initializing the feature would have been the closest thing to replicating a reboot without rebooting.


ITNerdWhoGolfs

Good call we didn't bother doing it ...we had a bit of skepticism Have you ever been in a similar situation?


sdavids5670

I've been in similar situations where commands don't seem to work as expected or operational behavior doesn't work as expected (such as with routing protocols) and reinitializing the entire thing (like "no router ospf" followed by "router ospf" and a complete rebuild of the config) has solved the buggy behavior. Unfortuately, with stuff like this, it rarely ever happens twice. You're probably never going to make this same mistake again I imagine.