VLAN flapping

[drnteam]

Hi,

We are using 3750 switch as core switch, and we are getting an error message VLAN flapping between two switch ports can any one advicxe the cause of this.

[mahmoodmkl]

Hi

this is related to STP loop,check for the uplink or redundant connections.

Thanks

Mahmood

[drnteam]

HI,

I identified the loop and shut down the PC. Its was generating the below error. What exactly is the cause of the error. There was a laptop connected on that port.

FastEthernet0/14 relearning 18 addrs per min

May 7 04:53:44.589 GMT: %RTD-1-ADDR_FLAP: FastEthernet0/14 relearning 27 addrs per min

[mahmoodmkl]

Hi

This is the error message when there is a loop in the network.Usually a port learns one address if it is access port.if it is trunk port it will have many address but it not learn so fast.

Thanks

Mahmood