High CPU loads Cisco 2960
07/06/2012 Leave a comment
Lately I have been working a lot with Cisco 2960 access switches, with different IOS versions. I noticed that the C2960-48TC-L and C2960-48PST-L types had high cpu loads. After contacting Cisco it looks like it’s not a bug, but a “feature”.
On the switch there is a process called “Hulc LED process”. In short this proccess is responsible for link detection. When a switch has al it’s ports with the “connected” status there is no problem. If one or more ports has it’s status “not connected” the process spikes up to 80%.
Cisco’s solution after reading the official Cisco forum: the process as mentioned above is working as designed and if you want to temper the cpu load, manually shutdown the “not connected” ports.
I think it’s a really crappy answer because a not connected port can have a turned off computer behind it.
Nevertheless the solution works. After manually shutting down the “not connected” ports the process cpu load drops to normal values.