Routing involves routers communicating with each other. To do this, routers need to know information about each other. These routers are called neighbor routers, and are configured in each routing protocol. Each neighbor has custom settings since some routers may have functionality others routers lack. Neighbour routers are sometimes called peers.

Generally neighbor routers must be configured, and discovered by the rest of the network before they can be integrated to the routing calculations. This is a combination of the network administrator configuring the new router with its neighbor router addresses, and the routing network discovering the new router, such as the hello packets in OSPF. That discovery initiates communication between the new router and the rest of the network.