In one embodiment, a first router associated with a first network node sends a first map lookup that includes a particular device identifier associated with a second network node to a mapping service that maintains a plurality of mappings that associate device identifiers with device locations. The first router receives, from a second router associated with the second network node, a map response that includes a particular device location that corresponds to the particular device identifier for the second network node. The first router establishes a secure session with the second router, and determines, based on the secure session, whether the second router is authorized to reply for the particular device identifier associated with the second network node.