Distance Vector Routing Vs. Link State Routing
The process by which information or data is passed through a network or internet to its destination is known as routing. There are a lot of routing techniques that work to make this routing system efficient.
Dynamic routing is one of those techniques that ensure optimal data routing. It analyzes the network circuit and finds the best path for the data to be passed on. That being said, what are Distance Vector routing and Link State routing? What are their differences?
Distance Vector routing and Link State routing are two types of dynamic routing techniques. The technique in which a router just needs the direction and distance to pass on information is distance vector routing. While Link state routing builds its own path through the network topology.
Both these routing techniques are used by the routers to pass on information depending on which will be the most efficient. To have a deeper understanding of how routing is done and about dynamic routing, one must have good knowledge about these two classes of dynamic routing and their differences. So let’s take a look at what these two routing techniques are and how they are different from each other.
Distance Vector Routing
Distance vector routing is a dynamic routing technique that doesn’t require the exact location of the destination to send its data or information. As it can be seen from the name, distance and direction (vector) are two things that are required for executing this technique. So what the router does in this technique is to calculate the distance of every neighboring router and pass the information through to the destination’s direction.
It uses the Bellman-Ford Algorithm for constructing the routing path through which the information will be passed along. The router chooses to share its knowledge about the topology with the local routers for updating the topology continuously. This process is simultaneous and keeps happening in regular intervals. It then calculates the best route to take based on the distance (the fewest number of hops).
The distance vector routing doesn’t utilize the CPU and memory much for routing. It is a very simple process and easily manageable. Traffic is less in this routing process. But the convergence time for this technique is very slow for which good data will reach faster but a bad one will take a long time. It also suffers from the count to infinity problem. There is no hierarchical structure present in the case of this routing technique.
It also has a looping problem which means the information will be in a loop forever. The practical implementation of this kind of routing is Routing Information Protocol and Interior Gateway Protocol.
Link State Routing
Link State Routing is a dynamic routing algorithm where the router receives the complete information about its surrounding routers and shares this knowledge with the whole network. The information about all the neighboring routers is spread through flooding to the whole network. It is also known as the shortest path first protocol. Link state routing protocol tends to have the whole picture of the network topology.
It uses Dijkstra’s Algorithm to construct its routing path through which the information is to be passed along in the network. There is no simultaneous exchange of information between the routers in the case of this routing technique. The only time the routing table is updated is when there is a change of information. It also only updates the link state rather than updating the whole topology.
Link State Routing measures the optimal route for passing information based on the least cost. As a result, the convergence time of the link-state routing is very fast, and there is very little chance of any error. There is high utilization of CPU and memory in the case of link-state routing. Also, it is a very complex technique and is not easily manageable. For that, to make the whole process smoother trained network administrators are needed.
In the Link State routing, the nodes have a hierarchical structure. It suffers from heavy traffic in the network system due to the overflow of packets. This can be solved using the Time to Live (TTL) field. Practical implementation of link-state routing would be Open Shortest Path First and Intermediate System to Intermediate System.
Distance Vector Routing Vs. Link State Routing
Both these dynamic routing techniques use different ways to pass on the information more efficiently. There is a lot of difference between these two classes of dynamic routing. They are discussed below:
Algorithm:
The Distance Vector routing uses the Bellman-Ford algorithm. While the Link State routing uses Dijkstra’s algorithm.
Tactic:
The Distance Vector routing uses the topology information for neighboring routers in a network for passing on information. While the Link State algorithm has the whole knowledge about the network topology.
Bandwidth Usage:
Distance Vector Routing doesn’t require a lot of bandwidth since there is no flooding in the network and it is used in the local networks. While Link State requires more bandwidth for sending large packets of information and flooding the network.
Path Construction:
The Distance Vector Routing’s path construction is based on the shortest distance (least number of hops). While State Link routing’s path is constructed based on the cost.
Table Updates:
Distance Vector routing keeps updating its routing table simultaneously throughout its operation. While State Link Routing only updates the routing table when there is a change in link state.
CPU and Memory Usage:
Distance Vector Routing doesn’t need high utilization of CPU and memory. Whereas, State Link routing requires intensive utilization of them.
Simplicity Level:
Distance Vector routing is very simple to operate. State Link routing is very complex and requires trained administrators.
Traffic Level:
The traffic level is very less in Distance Vector routing while it is very high for State Link routing.
Convergence Rate:
The convergence rate is rather slow in the Distance Vector Routing while it is fast in the State Link Routing.
Count To Infinity Problems:
The count to infinity problem is present in Distance vector routing while it is absent in State Link Routing.
Looping:
The looping problem is present in the Distance Vector routing while it is not present in the State Link routing.
