To "properly" monitor flows, Cisco says to monitor flows from all active interfaces on a given Layer 3 device. That would mean a router with two interfaces needs two interface licenses.
Can anyone confirm if this is true?
As an example, if I have a router with a fast ethernet interface connected to a core switch and a T1 serial link connected to a remote site, is it 'good enough' to just montior the serial link if your goal is to see all traffic to and from the remote site? Or do I need to burn another license to monitor the fast ethernet interface as well.
