The Next Hop Resolution Protocol (NHRP) is an extension of the ATM ARP routing mechanism[1] that is sometimes used to improve the efficiency of routing computer network traffic over a non-broadcast, multiple access (NBMA) network.
[6] NHRP is implemented by means of next-hop servers across IP subnets.
[7] NHRP forms a part of the Multiprotocol Encapsulation over ATM (MPOA) protocol as described in RFC 2684.
[8][9] It also plays a role in Cisco's Dynamic Multipoint Virtual Private Network.
[1] From RFC 2332: "[NHRP] allows a source station (a host or router), wishing to communicate over [an NBMA] subnetwork, to determine the internetworking layer addresses and NBMA addresses of suitable 'NBMA next hops' toward a destination station."