Department of Software EngineeringMehran University of Engineering and Technology, Jamshoro

Course: SW321 – Computer networks and managementInstructor Rabeea Jaffari Practical/Lab No. 08,09Date CLOs CLO-3: P5 & CLO-4: P3Signature Assessment Score 1 Mark

Topic To configure the distance vector routing protocol on two routersObjectives - To learn the concept of Dynamic routing and to configure RIP

distance vector routing protocol on two and three routers.

Lab Discussion: Theoretical concepts and Procedural steps

DYNAMIC ROUTING: Configuring routing table entries manually was referred to as static routing. Dynamic routing protocols (from now on, called routing protocols) set the routing tables automatically without human intervention. Routers and hosts that run routing protocols exchange routing protocol messages related to network paths and node conditions and use these messages to compute paths between routers and hosts.

Most routing protocols implement a shortest-path algorithm. Based on the method used to compute the shortest or least-cost paths, one distinguishes between distance vector and link state routing protocols. In a distance vector routing protocol, neighboring routers send the content of their routing tables to each other and update the routing tables based on the received routing tables. In a link state routing protocol, each router advertises the cost of each of its interfaces to all routers in the network.

AUTONOMOUS SYSTEMS:

The notion of an autonomous system (AS) is central to the understanding of routing protocols on the Internet. An autonomous system is a group of IP networks under the authority of a single administration. The entire Internet is carved up into a large number of autonomous systems.Examples of autonomous systems are the campus network of a university and the backbone network of a global network service provider. On the Internet, dynamic routing within an autonomous system (intra) and between autonomous systems (inter) is handled by different types of routing protocols. A routing protocol that is concerned with routing within an autonomous system is called an intradomain routing protocol or interior gateway protocol (IGP). A routing protocol that determines routes between autonomous systems is called an interdomain routing protocol or exterior gateway protocol (EGP).

In this lab, we’ll study the two most common intradomain distance vector protocol, namely, the Routing Information Protocol (RIP).

ROUTING INFORMATION PROTOCOL (RIP):

RIP is one of the oldest dynamic routing protocols on the Internet that is still in use. This lab uses the latest revision of RIP, RIPv2 (RIP version 2).RIP is an intradomain routing protocol that uses a distance vector approach to determine the paths between routers. RIP minimizes the number of hops on each path, where each point-to-point link or LAN constitutes a hop.Each RIP-enabled router periodically sends the content of its routing table to all its neighboring routers in an update message. For each routing table entry, the router sends the destination (host IP address or network IP address and associated prefix) and the distance to the destination measured in hops. When a router receives an update message from a neighboring router, it updates its own routing table.

Configuring RIP on Packet Tracer:

Main commands are as follows:

Router(config) #router rip Enables RIP as a routing protocolRouter(config-router) #network w.x.y.z w.x.y.z is the network number of the

directly connected network (ip address without subnet) that you want to advertise.

Let’s apply RIP protocol on the following topology.

Now, we will follow the steps as mentioned below:

1. We will assign IP addresses to all the fast Ethernet and serial interfaces respectively. (as done in previous lab of static routing)

2. We will change the state of the interfaces from down to UP. 3. Then, after we are done with the basic step, we will apply RIP protocol

commands on both routers.

Configuration of Router 0 i.e. configuring both serial and fastethernet interfaces.

Configurations of Router 1:

Assigning IP address to PC0

Assigning IP address to PC1

Router 0In order to apply protocol RIP on Router 0, we will write the following set of commands. Router(config)# router rip Router(config-router)# network 192.168.1.0 Router(config-router)# network 192.168.2.0 Router(config-router)# network 192.168.3.0 Router(config-router)#exit

Router 1In order to apply protocol RIP, we will write the following set of commands on Router 1 as well. Router(config)# router rip Router(config-router)# network 192.168.1.0 Router(config-router)# network 192.168.2.0 Router(config-router)# network 192.168.3.0 Router(config-router)#exit

Another important thing here is that we will add all the networks that we are using in our topology. Here in this particular example only two networks x.x.1.0 and x.x.2.0 are used so that’s why their network addresses have been added to the RIP protocol. Now, you can check it. Traffic is enabled and you can easily send data from PC0 to PC1.

Lab TasksSubmission Date:

1. Reconfigure the above topology to add a third router in it and explore how RIP detects changes to the network topology and how long it takes until RIP updates the routing tables. Use the command show ip routeon the routers to compare the routing tables of the Routers before the topology was changed and after new router has been added and the routing tables have been updated.

2. Discuss the time it took to update the routing tables.