How should I config if a router has four interfaces

Question

if router has four interfaces as follow

fa0 --WAN 1 (ISP A)

fa1--WAN 2 (ISP B)

fa2 -- LAN 1 (Dept A)

fa3-- LAN 2 (Dept B)

How should I config netflow? like that?

int fa0
ip flow ingress
ip flow egress
ip route-cache flow

int fa1
ip flow ingress
ip flow egress
ip route-cache flow

leave int fa2 and fa3 blank

Donald_Francis · Answer

Just my 2 cents but I would just put it on your wan interfaces.