3 ms·
Yeah, if you read a little further down we worked with the vendor to get them extensive diagnostics and get to the root problem. TL;DR: Lock contention on the C
by imbriaco 14y ago
Yeah, if you read a little further down we worked with the vendor to get them extensive diagnostics and get to the root problem. TL;DR: Lock contention on the CAM table.
"We have worked with our network vendor to provide diagnostic information which led them to discover the root cause for the MAC learning issues. We expect a final fix for this issue within the next week or so and will be deploying a software update to our switches at that time. In the mean time we are closely monitoring our aggregation to access layer capacity and have a workaround process if the problem comes up again."
In terms of network scalability, a properly designed layer 2 topology can scale quite a bit farther than our current needs. This is very much the least disruptive change we could introduce to solve the immediate network problems while we work on the future architecture.
- xtacy 14y agoOoh, lock contention on the hardware CAM table or the software in the switch that handles these updates? The first time I am hearing about this bug :-) Thanks a lot for sharing this bug story!
- imbriaco 14y agoIt was a lock that was being held by software but also prevented hardware updates to certain hash locations in the CAM. So MAC addresses that hashed to those locations couldn't be learned by any means.
- brooksbp 14y agoI wonder what hash was in use. Also, what workaround were you using to prevent flooding while this issue was happening?
- masklinn 14y ago> TL;DR: Lock contention on the CAM table. It's not really a tl;dr since (as far as I can see) it wasn't in the original post, though.