On my Cisco 877 router (running in VPN mode) I have the ip nbar protocol-discovery enabled on the VLAN 1 interface. I also have Netflow on a local PC. When I run "show ip nbar protocol-discovery interface vlan 1" it shows that edonkey and skype are running through the interface!
I'm not sure how long the data is kept on the router or if it's refreshed every few minutes, but I have just run it when only 4 IP printers and 1 laptop are on the network and these 2 apps are running apparently. I have checked the laptop and can't find the P2P edonkey app or Skype app. Why is it shwing up as nbar is deep packet inspection?