After consulting some syslogs, I have found that one of the stack ports on our 3750 stack has been flapping (up and down) for several days. What prompted me to look at the logs is the whole stack rebooted at random durning the night.
After the reboot the stack ports flapped again for a short while then stopped. The flapping stopped for a few hours then returned. The "sho switch stack-ports" shows everything as being "OK".
Another odd thing, is that NTP on the problematic stack no longer is functioning. Other switches on our network are pointed to the same public NTP server seem to be working just fine.
I have check the normal: Stack cables are "homed" in and connected in the proper order according to the Cisco spec. I preformed an administrative reload of the switch stack and the symptoms still are present. I plan on switching out the stack cable to see if this is it. The stack is running IOS 12.2(35)SE2. The stack consist of 3 WS-C3750G-24T switches.
Any thoughts or comments? I am thinking this may be a cable issue, port issue, or IOS bug??? Anything would be appreciated before I open a TAC.