Recently I've migrated a filer from 6509 to 4900M. I copied the same setup from 6509 to 4900M, but It caused problem. On the filer, a virtual interface is trunk between 4 physical interface sharing the same mac address and IP. The setup on 6509 was to have 2 L2 port channels and each port channel has 2 physical interfaces. It worked well. However, when it migrated to 4900M, the switch has very high CPU utilization. lt looks fine on the filer side though. In order to fix it, I created a port channel that contains 4 physical interfaces at 4900M and it backs to normal. I wonder how come it wasn't a problem at 6509, but at 4900M. Any idea?
I have this problem too.