Routing information protocol is a method of determining the distance and direction for information to move over a network or the Internet. This protocol uses distance-vector routing, one of the two main methods for mapping network spaces. Approximately every 30 seconds, a routing information protocol-based router will send out a packet of information to nearby routers telling them what it knows about the connected network. This information is used to find the easiest path from one network place to another, speeding up network transmissions.
The two factors the routing information protocol uses to create a network map are distance and direction. Neither of these terms has any standard measurement values. Direction is the final destination of its information. Distance is the number of hops—any bottlenecking, non-pathway, locations—required to get it there.
The most common hops on a network are other routers. These hops take the information traveling through the network or Internet and redirect them based on their knowledge of the network. Routing information protocol bases distance on the number of hops made; the more hops, the worse the pathway. This protocol limits the number of hops used to 15. Any more hops, and the distance is considered infinite and will not transmit.
Direction is both the destination of the information and the next hop address in the system. The protocol attempts to locate the shortest distance based on direction. For example, the system calculates the route distance by taking two points, the starting point and the endpoint, as fixed. It then determines the direction to all nearby hops, then all the ones connected to them. If a particular hop takes the information in the wrong direction, often meaning it forms a loop, the pathway is discarded.
This protocol is based on constant updates from nearby systems. These updates contain any new or altered information relating to the immediate network. Since every routing information protocol-based router is receiving this information, the entire network is constantly being remapped. This will let the routing system make the best decisions for its information pathways.
For the most part, routing information protocol is a dead technology. The methods it uses require too much bandwidth and network time. When networks were smaller and the Internet less complicated, it worked well, but now its limitations are too great for many systems to work around. It has been replaced with routing protocols that are more adaptive and less centralized to hardware systems.