Hi there,
i have a set of 3 C9200L-48P-4G within a stack. these are on 17.12.02 as i upgraded them due to encountering what i thought was bug CSCwc41288,
since the upgrade, the switches ran fine for months and then the observed behavior has come back again yet the counters for the issue haven't incremented.
At present, we observe link down/up events on the fibre uplink on this switch and on the other switch we are not seeing a link flap but loop guard block/unblock as the particular route is a redundant link at present.
i have changed every fibre patch lead at both ends, replaced the SFP modules and checked the light levels both ends. i tried a different uplink port but still no joy and even tried a different fibre pair between the two buildings.
Any ideas?
