[nsp] IP accounting

[James hampton]

   It was suggested that I use ip accounting to help track hackers on our servers. It seems to be supported on our Cat 3548 switch (IOS) and our core router. However when I config "ip accounting" on the switch vlan int, than do a "show ip accounting" I never get any resulting data. I have the same results from the Ethernet port on the router that feeds the switch. Do I need cef enabled, or ip route-cache on the switch ints? Is there something else Im missing?
James