ROUTING is the process of selecting a path through an internetwork over which to transmit packets to a destination host or hosts and then having devices called routers forward the packets to those hosts.
A routing protocol specifies how routers communicate with each other to distribute information that enables them to select routes between any two nodes on a computer network.
Watch the Video lectures on Routing Basics (click the following links)
- TCP-IP Routing Basics
- DVR :Distance Vector Routing
- Count to Infinity: Node Instability Problem in Routing
- RIP : Routing Information Protocol
- RIP Timers
- Link State Routing and Open Shortest Path First (Part-1)
- Link State Routing and Open Shortest Path First (Part -2)
Expertvision 
Dear Professor, what factors are depend on sending time of its routing table of node in a periodic update ?
It depends on complex distributed algorithms, and is often referred to as the network’s control plane. The frequency of these periodic updates varies from protocol to protocol, but it is typically on the order of several seconds to several minutes. Whenever a node’s routing table changes, it sends an update to its neighbors, which may lead to a change in their tables, causing them to send an update to their neighbors.
As you have mentioned, in internet network we need to use dynamic routing. Where static routing is used?
In Static routing, routing table is configured manually rather than dynamically self configuring. Static routes are fixed and do not change if the network is changed or reconfigured.
1. It is suitable for small networks that require only one or two routes.
2. Mainly used for defining default route, that is to define an exit point from a router when no other routes are matching with the table entries.
3. Provide a temporary backup in the event when dynamic route is unavailable.
In some case both dynamic routing and static routing are usually used on a router to maximise routing efficiency
Why do OSPF messages propagate faster than RIP messages?
OSPF shares the information using flooding techniques, which means that every router is getting updated with any change in other router. Whereas in RIP the updatuon is shared only with neighbors routers which eventually results in slow convergence