The other differences of both types of routing protocols are as follows. On the other hand, link state routing protocols require more cpu power and memory than distance vector routing protocol algorithms. Learn which type of routing protocol could work best in your environment. Distancevector routing protocols use the bellmanford algorithm and fordfulkerson algorithm to calculate the best route. Computer network link state routing algorithm javatpoint. Routing algorithms distance vector, link state study. In this video, russ goes through the differences between a distance vector and link state routing protocol. Distance vector rip linkstate ospf, isis path vector bgp hybrid eigrp figure 1. The linkstate vector routing lsvr working group is chartered to develop and document. State the major difference between distance vector routing and link state routing. Link state routing protocol reduces the network data overhead, unlike distance vector routing protocol, by using partial computation when a link metrics changes in the network.
The routing protocols include destination sequenced distance vector dsdv, dynamic source routing dsr, optimized link state routing algorithm olsr and temporally ordered routing algorithm tora. The dijkstras algorithm is an iterative, and it has the property that after k th iteration of the algorithm, the least cost paths are well known for k destination nodes. A link state protocol would choose the a c d b path because its using a faster medium 100 mb ethernet. These routing schemes are classified as link state routing lsr and distance vector. The link state routing algorithm is also known as dijkstras algorithm which is used to find the shortest path from one node to every other node in the network. They compare their routing table against the information they receive from their neighbors if it matches, they are good. Link state protocols send information about directly connected links to all the routers in the network. Linkstate routing, in contrast, requires that all routers know about the paths reachable by all other routers in the network. Understanding the ospf linkstate routing protocol ipv4. This is because shortest path between any 2 nodes contains at most n1 edges if there are n nodes in the graph. Therefore, the efficiency of transmission can be measured by the number of links to reach the destination. But in link state, routing protocols updates the network only when a change in network happens, and it is created to overcome the drawbacks of distance vector protocol.
Contrast with link state protocol and path vector protocol. Distance vector routing uses udp at transport layer. Routing is the mechanism of transferring information from a source to destination across an internetwork. Comparison between distance vector routing and link state routing. Difference between linkstate and distance vector protocols. Goals for todays lecture learning about routing protocols link state global view distance vector local view maintain sanity. Examples of linkstate routing protocols include open shortest path first ospf and intermediate system to intermediate system isis the linkstate protocol is performed by. Another approach to loopavoidance if one has a picture of the entire network, can.
Should you use distance vector or link state routing. Distance vector routing dvr a 3 keys to understand how this algorithm works. In this example, it would be better to run a link state routing protocol, but if all the links in the network are the same speed, then a distance vector protocol is better. Link state routing protocol an overview sciencedirect. In particular, this chapter discusses the theory behind types of routing. This aspect of distance vector routing is sometimes referred to as routing by rumor.
Dale liu, in cisco router and switch forensics, 2009. Computer network distance vector routing algorithm. Distance vector protocols date back to the arpanet network in the early 1970s. Distance vector protocols send their entire routing table to directly connected neighbors.
Distance vector protocols have slow convergence and suffer from the counttoinfinity problem details of which you can find here. Distance vector routing algorithm example gate vidyalay. Distance vector protocol, linkstate protocol, or pathvector protocol behavior. Introduction to link state routing protocols what is. One problem with distancevector routing is that it can send traffic to slower links which have less hops than faster links which have more hops, whereas linkstate routing doesnt care about the number of hops, only the cost, to get to the destination network, and the cost can reflect something important like the bandwidth of the path. Routing protocol classification and distance vector vs link state. Link state routing protocols have a totally different mechanism for the exchange of routing information and the calculation of network paths. The distance vector routing and link state routing are the two of routing algorithms, categorised depending on the way the routing tables are updated. Link state routing protocols are a different breed and make of routing protocols as they go about the process in a remarkably different way. Describe the distance vector routing protocol with examples.
Distance vector distance vector routing protocols are based on bellma and ford algorithms. In computer communication theory relating to packetswitched networks, a distancevector routing protocol is one of the two major classes of routing protocols, the other major class being the linkstate protocol. Since different environments have different requirements, there are different routing protocols. Another way of calculating the best route across a network is based on link cost, and is implemented through linkstate routing protocols.
Routers employ routing protocols to forward packets. The router share its knowledge about the whole network to its neighbors and accordingly updates table based on its neighbors. Recall example from distance vector routing where network partitions. Flooding can result in infinite looping which can be solved by using time to leave ttl field. Linkstate routing distancevector routing goal of today. Routing tables are prepared total n1 times if there are n routers in the given network. Link state routing protocols converge more quickly and they are less prone to routing loops than distance vector routing protocols. Algorithms may be dynamic, where the routers make decisions based on information they gather, and the routes change over time, adaptively.
Difference between distance vector routing and link state routing. Each router shares its knowledge about the entire as with neighbours. Linkstate routing protocols are one of the two main classes of routing protocols used in packet switching networks for computer communications, the other being distancevector routing protocols. Compared to linkstate protocols, which require a router to inform all the nodes in a network of topology changes, distancevector routing protocols have less. It is a dynamic routing algorithm in which each router computes distance between itself and each possible destination i. The protocol internet routing works on bgp is a distance. If the network is stable, link state protocol refloods each lsa regularly, ex. Rip v1, rip v2, and igrp are distance vector protocols. Linkstate and distance vector arent actual routing protocols, but types of routing protocol. Routing protocol classification and distance vector. Distance vector routing algorithm simplifies the routing process by assuming the cost of every link is one unit.
Prerequisite distance vector routing, dijkstra algorithm, distance vector routing vs link state routing, ospf, rip unicast unicast means the transmission from a single sender to a single receiver. Link state routing link state routing same assumptionsgoals, but different idea than dv. A distance vector is a decentralized routing algorithm that requires that each router in the network inform its neighboring router about the. Pdf mobile adhoc networks are primarily classified for their dynamic topology and lack of infrastructure. Measures like split horizon and poison reverse are employed to avoid routing loops. Algorithms may be static, the routing decisions are made ahead of time, with information about the network topology and capacity, then loaded into the routers. The term distance vector refers to the fact that the protocol manipulates. Distance vector routing protocols are popular in small networks with few routers but as network size increase distance vector routing protocols cannot provide the required services and thus link state routing protocols are popular in all types and sizes of networks. Classful legacy or classless protocol for example, ipv4 routing prot ocols are classified as.
Routing protocols compared distance vector, path vector. Much like some complicated but capable distance vector routing protocols, link state routing protocols use a lot of calculation overhead when devising routing table. Link state routing same goal as distance vector, but different approach. It makes use of dijkastras algorithm for making routing tables. Distance vector routing it is a dynamic routing algorithm in which each router computes distance between itself and each possible destination i. Link state protocols use a hierarchical structure that limits the distance that a. Tell all routers the topology and have each compute best paths two phases. A routing protocol specifies how routers communicate with each other, distributing information that enables them to select routes between any two nodes on a computer network.
It is a point to point communication between sender and receiver. As we have discussed in the previous lessons a distance vector routing protocol do not posses the topological information about the network but instead rely on the neighbors information, which is the reason this method is known as routing. Distance vector dynamic routing protocol periodically send information about their known routes to their connected neighbors. Routing information protocol is a distance vector routing protocol that is based on rfcs 38, 1723, and 2453. Lecture overview distance vector assume each router knows its own address and cost to reach each of its directly connected neighbors bellmanford algorithm distributed route computation using only neighbors info mitigating loops split horizon and posion reverse cse 123 lecture. Much like some complicated but capable distancevector routing protocols, link state routing protocols use a lot of calculation overhead when devising.
Topology dissemination flooding new news travels fast. What is the difference between link state routing and. Outline s routing in telephone networks s distancevector routing s linkstate routing s choosing link costs s hierarchical routing s internet routing protocols. Distance vector routing protocols require very little overhead as compared to link state routing protocols as measured by memory and processor power while the link state routing protocols do not rely solely on the information from the neighbours or adjacent router in order to calculate route information. Difference between distance vector routing and link state. Assume each router knows its own address and cost to reach each of its directly connected neighbors. Distancevector routing protocols use the bellmanford algorithm, fordfulkerson algorithm, or dual fsm in the case of cisco. Distance vector routing suffers from count to infinity problem. Distance vector protocols are slow and have chances for loops. Also, link state routing protocols only send updates to neighboring routers, unlike distance vector protocols, which send the entire routing table.