I've now seen the strangest thing ever on one of our switches. Earlier today we had a section of one of our schools lose wired and wireless connectivity. I checked and saw that one of our switches had stopped responding and appeared offline.
Logging into a neighboring switch the trunk port (gi0/2) was showing up/up. Ok wierd. So I went out to the site and consoled into the 'down' switch. It's trunk port (also Gi0/2) was also showing up/up. I unplugged the cable from gi0/2 and my console showed Fa0/24 going down/down. Huh? I plugged it back into Gi0/2 and console reported Fa0/24 going up/up.
Totally baffled now, I configured the empty Gi0/1 as a trunk and connect the cable to that port instead. The console showed Fa0/24 go down/down and then Fa0/17 come up/up! Yet still no connectivity/visibility to the next upstream switch.
I reloaded the switch from the console, not saving any changes I had made, and it came back up - now connected and able to see the next switch.
Is this a sign of the switch giving up the ghost? Has anyone experienced a switch getting it's own ports confused like this?
Even if I can't really 'fix' it, it's one of the funniest things I've ever seen a Cisco switch do. :)