The Next Hop Resolution Protocol (NHRP) is an extension of the ATM ARP routing mechanism
that is sometimes used to improve the efficiency of routing computer network traffic over
Non-Broadcast, Multiple Access (NBMA) Networks.
It is defined in
IETF
The Internet Engineering Task Force (IETF) is a standards organization for the Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster or requirements and ...
RFC 2332, and further described in RFC 2333. It can be used by a sender to determine a route with the fewest hops to a receiver. The protocol differs from
ARP-type protocols in that it allows routing optimization across multiple IP subnets. NHRP is implemented by means of next-hop servers across IP subnets. The NHRP forms a part of the
Multiprotocol Encapsulation over ATM (MPOA) protocol as described in RFC 2684.
It also plays a role in Cisco's
Dynamic Multipoint Virtual Private Network.
A limitation of NHRP is its inability to improve
multicast
In computer networking, multicast is group communication where data transmission is addressed to a group of destination computers simultaneously. Multicast can be one-to-many or many-to-many distribution. Multicast should not be confused wit ...
protocols.
Description
From RFC 2332:
"
HRPallows a source station (a
host
A host is a person responsible for guests at an event or for providing hospitality during it.
Host may also refer to:
Places
*Host, Pennsylvania, a village in Berks County
People
* Jim Host (born 1937), American businessman
* Michel Host ...
or
router), wishing to communicate over
n NBMAsubnetwork, to determine the internetworking layer addresses and NBMA addresses of suitable 'NBMA next hops' toward a destination station."
References
External links
OpenNHRP project page
Routing protocols
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