I recently noticed the CEF switching process on a 6509 was running at about 3% whereas it used to be < 1%.
Looking at the output of 'show ip cef events' there are constant adjacency updates for /32 addresses which are DHCP servers all hanging off a 3550 which is attached to one of the 6509 ports.
We are not using DHCP snooping.
I can't see anything wrong with the trunk between the 6509 and 3550. Logs don't reveal anything of interest.
I'm a bit stuck on where to look next to diagnose this - any suggestions?