Embodiments are directed to monitoring network traffic over a network. A monitoring engine may monitor flows of network packets in the network. The monitoring engine may determine an observation port that provided the network packets. The monitoring engine may determine primary network packets provided by an authoritative observation port based on which observation port provided the network packets and provide them to an analysis engine. The monitoring engine may discard a remainder of the network packets that may be associated with non-authoritative observation ports. The analysis engine may analyze the one or more primary network packets.