In computer networking, hop count refers to the number of routers through which data must pass between source and destination.[1] Each router along the data path constitutes a hop, as the data is moved from one Layer 3 network to another. Hop count is therefore a basic measurement of distance in an network.
By itself, hop count is not a useful metric 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. Nevertheless, some routing protocols such as RIP use hop count as their sole metric.[2]
Hop counts are often useful to find faults in a network, or to discover if routing is indeed correct. Utilities such as ping and traceroute are used in this capacity—by calculating the hop count to a given destination, as well as enumerating each hop along the way.