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by akira2501 824 days ago
We had Dell laptops with the dock. If you undocked the laptop under the right circumstances, which we could never determine, the dock would go into a mode where it would start spamming IEEE 802.3x PAUSE frames into the network as fast as it possibly could.

Our switches didn't handle this correctly and would forward the PAUSE frame as it if it were a broadcast. When this happened, the entire network would cease to function until the offending dock was found and disconnected.
2 comments
RedShift1 824 days ago
Sounds to me like something's crashing on disconnect, the ethernet watchdog notices a full receive buffer so it starts sending out pause frames, but the buffer never gets emptied anymore so the watchdog keeps sending out pause frames. Similar to like how you keep hearing the same audio sample over and over again when Windows bluescreens.
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caconym_ 824 days ago
I never root-caused it so thoroughly, but I have an Anker USB-C hub that causes exactly the same effect when it's unplugged from a machine while still connected to ethernet. Took me months to figure out wtf was happening.
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