Routing
Definition
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.
Why It Matters
Routing is a fundamental function of the internet. It is the process that allows a packet of data to travel from your computer, across potentially dozens of different networks and routers, to a server on the other side of the world.
Contextual Example
When you send an email, each router along the path examines the destination IP address of the packets and consults its routing table to decide where to forward them next. This decision is repeated at every hop until the packets reach their final destination.
Common Misunderstandings
- Routing is concerned with finding a path between networks (Layer 3). Switching is concerned with finding a path within a local network (Layer 2).
- Routing protocols like OSPF and BGP are used by routers to automatically build their routing tables.