2008 Oct 18
Routing is the process of moving a packet from one network to another on its way to its specified destination. Routers determine the path each packet takes across the network, specifying from hop to hop which network segments to take along the way. This is usually done dynamically meaning each router determines the next hop. There are also static routing options but they do not adapt to link damage or bandwidth issues. Sometimes security needs force a static route, esepcially for internal networks behind a firewall.
A router needs to know about the topology of the networks beyond those to which it is connected so it can decide where and if to transfer packets. The information a routre needs is proportional to the number of networks (not computers) in the internet.
There are a multiple routing protocols available such as: Routing Information Protocol (RIP), Open Shortest Path First (OSPF) protocol, and Border Gateway Protocol (BGP).
2005-2008