anyone know why does the alert mismatch vlan stick on a MS210 after you remove the cable , to remove the alert i have found i need to put the port into the far end vlan then revert back to original vlan ? , not a problem but just wondered as it remains for as long as you leave it ?
I believe the reason is that if you remove the cable, the port is still active, so to speak. It is not like you're issuing a "shutdown" on the port. The way to clear the mismatch usually is to correct it, so I guess when you change the VLAN, because the port is not connected to anything, it will accept the change and clear the error. When you change the VLAN back to original VLAN, again, there's nothing to mismatch with on the other side until you connect the cable again and the error appears again.
This is what I think is going on, let me know what you think?