First, I suppose you have swapped 5 and 6 in 2560, and you're talking about an HP 2650 ?
First of all, check in the log for any message which could be repeated many times
('sho log' command).
High CPU utilisation often occur with switching or routing loops.
Even if your statistics (3500pps/14Mb) are not really high for a switching loop, you should check following points :
- Is there any physical loop (Patch Cord between two ports, two link to another switch or hub) ?
- If there is one or more, is there an aggregation port and/or Spanning-tree enabled on the switch ?
- If spanning tree enabled and there is many switches in your network, try a 'show spanning-tree' in the CLI, and look at the Root Mac-address field. Is it the MAC address of your switch ?
--> Spanning tree can cause high CPU usage on the root switch in particular cases.
Look especially for a rooting loop :
- Check the routing tables of all other routers directly connected to your switch, and try to find loops (or opposite routes).
Begin with all next hops of the routing table of your switch.
Here are some other various questions :
- Your high CPU usage is constant, temporary, random ?
- Was the switch working properly before enabling routing ? What are new devices connected ?
- Where is located this switch in your network (Edge, Backbone, Servers connection, ...)
- How many Client/Server session should cross the switch in standard conditions ?
- Is the 'ip directed-broadcast' parameter enabled on the switch ? Is it indispensable ?
--> This can also cause burst in some cases.
Check the ratio of broadcast in the 'show interface' or 'sho stat' command.
Hope this will help you.
Arnaud