Distance Vector, Link State and Hybrid Routing Protocols
In this article you will learn about routing types, distance vector routing, link state routing and hybrid routing protocols.
Routing: The process of forwarding Internet Protocol (IP) packets from source to destination by selecting the best path that is available is known as routing. Routing is done by router, a layer 3 device. Generally there are Static Routing and Dynamic Routing
In static Routing, routes are added manually by the administrator. The static routing is not suited for large networks and increases the work of an administrator
In dynamic routing, routes are learnt automatically by the router. The dynamic routes are learnt using protocols like OSPF, Enhanced Interior Gateway Protocol and Routing Information Protocol (RIP) etc. Dynamic routing protocols help the router to take intelligent decisions that helps router to forward the packet to the destination in the best path.
When dynamic routing protocols are used, the routes are automatically updated. Routers exchange the information about the available routes among themselves. If any route or interface is down, it is automatically updated by the adjacent routers.
When there are two or more routes available to reach the destination, dynamic routing helps to select the best path among the available routes.
The best path is selected by considering congestion, bandwidth, administrative distance etc. Even the changes in the topology are automatically updated with the protocols that help the router to learn the routes.
The main disadvantages of using dynamic routing is that the dynamic routing protocols puts more load on CPU, consumes more bandwidth as more updates are shared at regular intervals.
Types of Dynamic Routing:
The protocols that help the router to perform dynamic routing are
1. Distance Vector Protocols
2. Link State Protocols
3. Hybrid Protocols
Distance Vector Protocols:
Bellman Ford algorithm is used in distance vector protocols and the routers that uses distance vector protocol does not have information about entire network. The routers advertise the distance value calculated. The distance value information is tabulated as routing table. Some of the examples of protocols that use distance vector protocol are RIP, RIP version2, RIPng, and IGRP etc
Link State Protocols:
The routers using link state protocol has the information about the entire topology. Based on the information about the topology, routers are capable of selecting best next hop independently. The best next hops are tabulated as routing table. OSPF, IS-IS (Intermediate System to Intermediate System) are some of the example of protocols that uses link state routing protocol.
The hybrid protocols are the combination of distance vector and link state routing protocols. They have the features of both the categories. EIGRP is the best example of Hybrid Protocol.
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- IGP Vs EGP
- What is Administrative Distance
- Difference between Static and Default Route
- Routing Metric Value, Hop Count, Bandwidth, Delay, Reliability, Load and Cost