Help selecting the right interface for TrafficFlow

Hi Guys,

I’m at a little bit of a loss on which interface(s) I should be using to record my traffic flow.
I have a dedicated target running nfacctd to capture the flows and dump them into mysql.

I have 2 x CCR1036-12G-4S setup with VRRP and bridged with my switches for redundancy, spanning tree (RSTP)
I uplink from each device to my provider via sfp1 (S-35LC20D’s).

ether2 and ether3 are in my bridge1 with VRRP on the bridge to handle failover.

So the question is, I just wish to export flows for traffic to/from my uplink, mainly just destination address to local and source address from local.
If I do all I’m literally seeing all traffic, including internal server - server, doing the bridge I for some reason only see inbound traffic.

Should I be choosing the ether2 and ether3 or the bridge1 for my trafficflow?

Cheers
Adam