I would like to talk about an interesting case encounter on S2700 series.
From time to time, CPU-usage rise from 20-30% to 50-60% and stay there for 10-30 minutes. Spanning tree protocol didn't flap and also there were no other events spotted inside the LAN network. Service running through the network is not impacted, traffic forwarding is running at line speed.
Well try to find together what is the root-cause.
Let's consider below topology, S2700 is located on access layer, connecting hosts and servers. Vlan 1, default vlan is passing through uplink ports as trunk and downlink as access ports. Also is the management vlan for all other switches in the network.