Dynamic Routing Protocols PDF

Dynamic Routing Protocols Dynamic routing protocols are another important type of routing protocol. It helps routers to add information to their routing tables from connected routers automatically. These types of protocols also send out topology updates whenever the network changes’ topological str...

Dynamic Routing Protocols Dynamic routing protocols are another important type of routing protocol. It helps routers to add information to their routing tables from connected routers automatically. These types of protocols also send out topology updates whenever the network changes’ topological structure. Dynamic routing protocols allow routers to automatically add information to their routing tables from connected routers. With these protocols, routers send out topology updates whenever the topological structure of the network changes. This means that the user doesn’t have to worry about keeping network paths up-to-date. One of the main advantages of dynamic routing protocols is that they reduce the need to manage configurations. The downside is that this comes at the cost of allocating resources like CPU and bandwidth to keep them running on an ongoing basis. OSPF, EIGRP, and RIP are considered to be dynamic routing protocols. Advantage: Easier to configure even on larger networks. It will be dynamically able to choose a different route in case if a link goes down. It helps you to do load balancing between multiple links. Disadvantage: Updates are shared between routers, so it consumes bandwidth. Routing protocols put an additional load on router CPU or RAM. Distance Vector Routing Protocol (DVR) – hop count Distance vector routing protocols are protocols that use distance to work out the best routing path for packets within a network. Distance Vector Protocols advertise their routing table to every directly connected neighbor at specific time intervals using lots of bandwidths and slow converge. In the Distance Vector routing protocol, when a route becomes unavailable, all routing tables need to be updated with new information. These protocols measure the distance based on how many hops data has to pass to get to its destination. The number of hops is essentially the number of routers it takes to reach the destination. Generally, distance vector protocols send a routing table full of information to neighboring devices. This approach makes them low investment for administrators as they can be deployed without much need to be managed. The only issue is that they require more bandwidth to send on the routing tables and can run into routing loops as well. Advantages: Updates of the network are exchanged periodically, and it is always broadcast. This protocol always trusts route on routing information received from neighbor routers. Disadvantages: As the routing information are exchanged periodically, unnecessary traffic is generated, which consumes available bandwidth. Link State Routing Protocol Link State Protocols take a unique approach to search the best routing path. In this protocol, the route is calculated based on the speed of the path to the destination and the cost of resources. Link state routing protocols use an algorithm to work this out. One of the key differences to a distance vector protocol is that link state protocols don’t send out routing tables; instead, routers notify each other when route changes are detected. Routers using the link state protocol creates three types of tables; neighbor table, topology table, and routing table. The neighbor table stores details of neighboring routers using the link state routing protocol, the topology table stores the whole network topology, and the routing table stores the most efficient routes. Link state routing protocol maintains below given three tables: Neighbor table: This table contains information about the neighbors of the router only. For example, adjacency has been formed. Topology table: This table stores information about the whole topology. For example, it contains both the best and backup routes to a particular advertised network. Routing table: This type of table contains all the best routes to the advertised network. Advantages: This protocol maintains separate tables for both the best route and the backup routes, so it has more knowledge of the inter-network than any other distance vector routing protocol. Concept of triggered updates are used, so it does not consume any unnecessary bandwidth. Partial updates will be triggered when there is a topology change, so it does not need to update where the whole routing table is exchanged. ROUTING INFORMATION PROTOCOL (RIP) In this scenario, we are using the Routing Information Protocol (RIP) as the dynamic routing protocol. So below mentioned diagram is the network plan for a small network..1 Fa0/0 192.168.5.0/24.2 Router 1 Configuration steps enable configuration terminal router rip network 192.168.2.0 network 192.168.1.0 Router 2 Configuration steps enable configuration terminal router rip network 192.168.2.0 network 192.168.3.0 network 192.168.5.0 Router 3 Configuration steps enable configuration terminal router rip network 192.168.3.0 network 192.168.4.0 ENHANCED INTERIOR GATEWAY ROUTING PROTOCOL (EIGRP) EIGRP (Enhanced Interior Gateway Routing Protocol), is a Cisco Proprietary Hybrid Routing Protocol. The configuration of EIGRP is similar to other Routing Protocols. So below mentioned diagram is the network plan for a small network..1 Fa0/0 192.168.5.0/24.2 Router 1 Configuration steps enable configuration terminal router eigrp 100 network 192.168.2.0 network 192.168.1.0 no auto-summary Router 2 Configuration steps enable configuration terminal router eigrp 100 network 192.168.2.0 network 192.168.3.0 network 192.168.5.0 no auto-summary Router 3 Configuration steps enable configuration terminal router eigrp 100 network 192.168.3.0 network 192.168.4.0 no auto-summary