Next Hop Definition

A next hop is the next router to which a packet is sent from any given router as it traverses a network on its journey to its final destination. In the event that the packet is at the final router in its journey, the next hop is the final destination.

A hop is the trip that a packet takes from one router to another, or from the final router to the destination. A packet, also referred to as a datagram, is the most fundamental unit of data transmission on the Internet and other TCP/IP (transmission control protocol/Internet protocol) networks. A router is an electronic device and/or software that connects at least two networks, such as two LANs (local area networks) or WANs (wide area networks), and forwards packets between them. Each packet can traverse dozens of routers (i.e., make dozens of hops) over the Internet as well as multiple routers within a large organization.

The next hop for any particular packet at any particular point in its journey is determined by both the IP address of its destination as contained in its header and the routing table in the router at that point. An IP (Internet protocol) address is a unique numeric identifier for each computer or router on a TCP/IP network. A routing table is a database in a router that stores and frequently updates the IP addresses of other routers and the most efficient routes to them.

Next hop resolution protocol (NHRP) is a method that can be used by a network device to determine the most direct route (i.e., with the fewest number of hops) to a destination.

Created November 17, 2005.
Copyright © 2005 The Linux Information Project. All Rights Reserved.