CSCvo12056 - C3850/C9300 - Stack cable authentication failed for cable inserted.

[padma]

I did code upgrades on  c3850edge switches from 3.6.6E to 16.6.4a. The upgrade went well & all switches in stack are running 16.6.4a but they kept reloading every 5-10mins.

after checking logs found as below :

*** Stack cable authentication failed for cable inserted on stack port 2 on switch 1 ***

Reloading chassis because cable auth failed on stack_port 0

   Chassis 1 reloading, reason - stack cable authentication failed

After replacing stack cables, everything was working fine. does anyone else had same issue with 16.6.4a code?

[Leo Laohoo]

Don't use 16.6.4a. Use 16.6.6 instead.

[ibrahimasank]

I just experienced the same issue on 16.6.6, swapping the cable fixed it, kinda weird that the first three stacking cables failed.