Router metrics are a specific set of data used by a router in order to make efficient routing decisions. These metrics usually appear in router table fields and include things like bandwidth, delay, path cost or a multitude of other data. Often the router uses a combination of these values to assist in determining the best method to transmit data to the appropriate destination.
Properly functioning routers attempt to use the most efficient path to transmit data by always using the easiest and fastest method for data delivery. Using the most effective connection method may not always be the cheapest solution, therefore network administrators can apply router metrics to each connection in order to determine which communication route is the most cost effective. In this way, router metrics help administrators to measure the cost effectiveness of a particular route.
There are numerous router metrics that can be used in order to determine the effectiveness of the route connections. One of the most commonly used metrics is called the weight metric. Routers that use static routes can have a weight assigned to them that correspond to their costs. If a route features a higher weight, it also means that there is a higher cost associated with that particular route as opposed to one with a lower weight. A network administrator can use this data in order to determine which route is most beneficial to the goals of the network.
Router Information Protocol (RIP) router metrics are also commonly used as a way to compare static routes. This is a distance protocol that uses a hop count in order to determine the best route through the network. The path that has the least amount of routed hops is considered to be the shortest one to the desired destination.
The Open Shortest Path First (OSPF) metric is often used as a cost measurement. In the field of computer networking, lower costs often lead to a faster interface and shorter transmission times. The OSPF route gathers the bandwidth of an interface and assigns it a cost metric that is used by administrators to indicate the speed of the route. Generally, higher speed connections have a lower cost than lower speed connections, therefore this is one of the more popular router metrics as it specifically measures the cost effectiveness of a router connection.