We've got an interesting scenario where a few different times at 3 different locations, we've had entire switch stacks where ports with Cisco Access Manager enabled stop forwarding traffic. Today we were able to determine that when this occurs, its because a device on one port starts reflecting mac addresses as if it has that device causing what appears to look like a loop to the switch stack. Unplugging the device and the CAM ports recover almost instantly. If a port didn't have CAM enabled, it never gets affected by this scenario, even if its on the same vlan.
C9300s, cloud managed in meraki dashboard
CAM enabled on majority of ports
Cisco 8851 desk phones
HP G6 thunderbolt docking station connected to the 8851 phone
So far TAC has just stated a loop occured and unplugging the offending device fixed the loop. This clearly isn't a normal loop as its pretty strange a phone or dock would cause this to occur only for the CAM enabled ports. Any ideas as to how CAM is playing a role in this?
