Hop (networking)

[1][2] Other protocols such as DHCP use the term "hop" to refer to the number of times a message has been forwarded.

[3] On a layer 3 network such as Internet Protocol (IP), each router along the data path constitutes a hop.

By itself, this metric is, however, not useful for determining the optimum network path, as it does not take into consideration the speed, load, reliability, or latency of any particular hop, but merely the total count.

This prevents packets from endlessly bouncing around the network in the event of routing errors.

Routers are capable of managing hop counts, but other types of network devices (e.g. Ethernet hubs and bridges) are not.

Routers modify IP packets as they are forwarded, decrementing the respective TTL or hop limit fields.

A routing table usually consists of a list of possible destination networks or IP addresses for which the next hop is known.

In other scenarios link layer resolution may require different methods such as a virtual private network which needs to determine the peer to send the packet to.

In a wireless ad hoc network, commonly, every participating node is also acting as a router.