Routing determines the path IP packets follow from source to destination. It is used in packet-switched networks like the Internet. Different routing methods are used to optimize speed, reliability, and performance.
Routing is the process of selecting a path for traffic in a network or between or across multiple networks. Broadly, routing is performed in many types of networks, including circuit-switched networks, such as the public switched telephone network (PSTN), and computer networks, such as the Internet.
The routing process starts when software on a host device uses a packet's contents, destination, or purpose to select a possible route from a routing table. A routing table is a repository of all the routes to all the destinations in use by a network.
What is routing? Learn how IP routing works, the definition of 'router,' what routing protocols are used on the Internet, and more.
Routers examine destination addresses, consult their routing tables, and forward packets hop by hop until they reach the right network. Understanding how this process works – and which protocols automate it – is foundational knowledge for anyone managing networks.
To provide connectivity between networks, routers must learn all network paths, select a single best path to each destination, and add the chosen path to the routing table. You can manually configure these paths on all routers or use a routing protocol.
Routing takes place at the network layer (layer 3) of the Open Systems Interconnection (OSI) reference model. On a TCP/IP internetwork, this means that routing involves delivering packets to destination IP addresses on the internetwork.
Routing is a fundamental concept in networking that allows data packets to travel from one device to another across interconnected networks. It ensures that data reaches the correct destination efficiently by determining the optimal path.