Techniques for associating a physical location with a network interface on an intermediate network node include receiving a data packet from a device connected to a network. Based on data in the data packet, a particular network interface is determined on a first hop intermediate network node. An identity for an entity that originated the data packet is determined based on data in the data packet. A possible physical location for the entity is determined based on the identity. The identity is associated with the possible physical location in an independent data source that is accessible over the network and different from the data packet. The particular network interface is associated with a highest confidence location for the device based on the possible physical location of the entity and any former locations associated with the particular network interface.