High CPU Utilization

[mahesh.mvk]

I have 2 switches, switch 1 and switch 2 connected via trunk and allowing the required VLANS. I had to decommission switch 2, so i removed the switchport trunk config before shutting down the interface on switch1.

This resulted in an excessive ARP requests and switch1 went to hung state, i shut down the trunk from switch 2 and everything back to normal.

I was looking for an explanation on why and what exactly happened.

 

[azazel1024]

I might not be parsing it correctly, but it sounds like you removed the trunking from switch 2 to switch 1, while the trunk from switch 1 to switch 2 was still intact and both were physically connected? If so, that sounds like a loopback to me. So if STP/RSTP was not activated...it would lock-up the switch.

I always setup all my trunking before physically connecting switches and the same with removing trunking, I disconnect the switches first.