We have a couple of Cisco 1700 routers that we currently monitor with Netflow Analyzer. What if have noticed in the new IOS 12.4 versions is the possibility to turn on ip flow ingress as well as ip flow egress on the interfaces. Turning on this options seem to give better statistics of outgoing traffic.
It also creates an extra interface null0 do you know if this interface also needs to be included in Netflow? Any idea about the purpose of this interface. (Why is it created when ip flow egress is configured)