Have a problem concerning high CPU (ip input) on our core cisco 7606 router. A GRE tunnel goes to another site [call it site A].
Data is transferred from site A over the tunnel to the local drives [via CIFS]. Data source is Netapp filers.
No matter the size [ say 50MB], the CPU on our cisco7606 spikes to 95-99% until the download is complete.
I see that alot of the traffic is process switch. I do not know why that would be so.
I have ensured fast switching and cef is enable on all ingress/egress paths.
Also the interfaces before traffic traverses the GRE tunnel on both ends have been tweaked to maximize MTU paths.
ip mtu 1400
ip tcp adjust-mss 1360
I would think this was a WAN issue, but the problem seems to occur from the NetApp boxes only.
My understanding of the Netapp is limited and only explained to me by the Netapp admin.
Duplicating the same transfer from a windows server does not impact the CPU at all.
Any ideas or suggestions ?
Thanks,
Pete
