I have a 3750 switch that bridges our corporate office to our Ethernet Network.
1- The port that bridges corporate office to the Ethernet Network is a L3 interface.
2- The port went into err-disable state, their was no recovery so the interface stayed down
3- The messages was "%PM-4-ERR_DISABLE: link-flap error detected on FA1/0/1" on the Cisco 3750
4- The port was receiving input errors and CRC's, counters incrementing fast
5- During a maintenace that was unrelated to the Cisco 3750, port Fa1/0/1flapped once then went into err-disable state
6- No other alarms in "show log" of the 3750
7- Can a loop on the network cause a port to flap once and place the port in err-disable state with the "link-flap error" alarm?
8- My question is general, need to know if this is possible. I know what caused a loop and I resolved it. Everything normalized but curious, did the 3750 mean to send an alarm stating "%PM-4-ERR_DISABLE: loopback error detected on"?
MN