As a best practice, do most of you who use Netflow enable it on all interfaces of a router, or just collect statistics from one or two interfaces? (I suppose the same question could be asked of SNMP.)
My Netflow collector receiving from a typical 2800 class router (one FastE, one Serial) shows the same stuff, but inversed between each interface, so I get a little confused on transmit vs receive as I look at each interface. I'm tempted to turn the Ethernet off and just watch the serial, but would I lose any flows or information doing so? Any reason to have both?