What Is A Routing Table?

Date First Published: 28th March 2022

Topic: Computer Networking

Subtopic: Network Identifiers

Article Type: Computer Terms & Definitions

Difficulty Level: 9/10

Learn more about what a routing table is in this article.

A routing table is a set of rules where routing information is stored and viewed in a table format that acts as a map, where the paths that data packets should take to reach every destination that the router is responsible for is recorded. It does not contain every possible destination. When a data packet is received, it is directed to the next network link until it reaches its final destination.

Routing tables contain routing entries, the necessary information to transmit a data packet to the recommended path towards its final destination, the location of routers based on their IP addresses, the next hop, which contains the IP address the packet will be forwarded to, and the interface, which contains the outgoing network interface that should be used by the device when transmitting the data packet to the next hop or final destination. In addition, the contents of the routing table can be shared with other nodes.

Routing tables can be maintained in two different ways. If they are maintained manually, it means that unless a network administrator manually alters them, the routing tables for static network devices will not alter. If they are maintained dynamically, it means that the routing tables are maintained automatically by devices through the use of routing protocols. These routing protocols exchange information about the network topology. Devices automatically respond to occurrences, such as device failures and network congestion.

Note:

Network devices, such as routers and switches use routing tables.

An example of the contents of a routing table can be seen below.