Next Hop Resolution Protocol (NHRP): Protocol used by routers to dynamically discover the MAC address of other routers and hosts connected to an NBMA network. These systems then can communicate directly without requiring traffic to use an intermediate hop, increasing performance in ATM, Frame Relay, SMDS, and X.25 environments. Also used in DMVPN and Tunnel networks.
A protocol to assist in routing decision by remote peers. Each remote peer registers it network/hosts in the NHRP server and that routing information can be leverage in the routing from remote to remote peers networks.