networking

Introduction A switch is a multi-input and multi-ouput networking

device which transfers packets from one input or inputs to output(s). A switch uses the header of a packet to identify destination address.

A Hub is a device that joins other computers to form a single network segment. All computers can communicate directly.

The simulation in this scenario using Opnet is aimed at examining the performance of networks connected using Hub only, a combination of Hub and Switch, Switch only and a combination Switches.

Opnet Simulation

After opening Opnet simulator, the topology was designed for the first scenario and named HubOnly:

Hub Only Specifying the Attributes of the Topology

The Opnet Set up

The Topology:

Configuring the nodesThe attributes were edited according to the question and saved.

Issue Encountered:In the OFF state Time(seconds) under Traffic Generation Parameters, we tried setting the value as 0.00, as specified in the guideline but it wasn’t possible as it kept showing error. So 0.00001 was used considering its tiny value.

Choosing StatisticsThe 4 individual statistics were chosen which are Delay, Traffic Received (packets/sec), Traffic sent (packets/sec) and collision count as shown below:

Configuring the simulationThe simulation was configured as stated in the guideline and the simulation time was put as 2 mins as shown below:

Running the Simulation The simulation run successfully and displayed the message below:

ResultAfter successfully running the simulation for the HubOnly, the results for the 4 selected criteria were captured. Delay

• Traffic Received (packet/sec)

• Traffic Sent (packet/sec)

• Collision Count)

Duplicating the Scenario: HubAndSwitch

The topology was duplicated to add Switch to it as shown below:

The HubAndSwitch simulation was run separately and the result obtained is shown below:• Delay

• Packet Received

Collision Count

• Packets Sent

Analysis: The result shows that the delay in the HubOnly is greater than the delay in HubAndSwitch. This is because Switch has a buffer for the frames reaching it and it shares the bandwidth equally among its nodes and has a table for all its nodes attached to it. These mechanisms which reduce delay do not exist in Hub which makes it faster using Switch.

• Traffic Received • Delay

Comparing and Analyzing the Result for HubOnly and HubAndSwitch

Analysis: The result shows that the packets received or delivered are more when a switched is attached in the topology than when only Hub is used. This is due less packet loss in a switched network.

Analysis: There is no much difference in terms of the packets sent in both networks because they are sending the same amount of packets.

• Collision Count• Traffic Sent

Comparing and Analyzing the Result for HubOnly and HubAndSwitch

Analysis: The Collision count in HubOnly network is very high because it floods the entire network with broadcast message when sending a packet. That’s why there is always high collision as the Hub does not know the destination address. But with a switch in the network, the collision has been greatly reduced because the switch has a table that contains the details of each node and there can easily send a packet without broadcasting the entire network. The reason why collision exists in the HubAndSwitch network is because of the Hub presence because when a packet is passed from the Switch part to the Hub nodes, the hub will flood the network with broadcast which causes collision to occur.

• SwitchANDSwitch• A new Scenario: A Scenario for SwitchOnly

Analysis: The Delay is highest in HubOnly, small in HubAndSwitch and very little in SwitchOnly and SwitchAndSwitch. This is because switch has a table for its entire host and contains the destination address for the message which brings no delay when sending packets. Unlike in Hub which congests the network with broadcast message for every packet and causes delay because of congestion.

• Packets Received• Delay

Comparing and Analyzing the Result for 4 scenarios

Analysis: The packets received in HubOnly are very less compared to the networks that contain switches simply because there is high loss of packets in the Hub network which is caused by collision.

Analysis: The packets sent are almost the same in all the topologies because they are generated from the nodes which have nothing to cause packet loss from the point of generation.

• Collision Count• Packets Sent

Comparing and Analyzing the Result for 4 scenarios

Analysis: In the networks where only switch and where 2 switches were used, there was no collision detection but there was collision where hub was used because of the continuous sending of broadcast messages by the Hub as it does not know the destination address. The collision is highest where only Hub was used, reduced by half where switch was used and no collision at all where only switch or 2 switches were used without hub.

Answers to Questions asked in the scenario Q: Explain why adding a switch makes the network perform better in terms of

throughput and delay ANS: The reason why the network performs better with switch addition is

because switches buffer the frames reaching it unlike a hub which does not buffer them. The switches maintain address tables for forwarding frames and they share the bandwidth equally among all the nodes attached to it. This leads to greater performance in terms of delay and throughput.

Q: We analyzed the collision counts of the hubs. Can you analyze the collision count of the switch?

ANS: Hubs do not check the destination address of frames reaching it. It just forwards them to other nodes which bring about collision count for Hubs. The case is different in Switches as they look at the destination address, buffer the frames and send them in accordance with their address table. This measure takes care of collision in switches and therefore no collision count.

Conclusion From the above results we can see that there is a better performance in switch

compared to hub. This is due to the mechanisms that a switch has which makes it perform better than.

A routing protocol is as a policy for easy communicating source to destination n devices. Into the other definition, Routing is the process of selecting best paths in a network. Although there are many types of routing protocols among them Link-state routing protocols (OSPF, EIGRP). Distance vector routing protocols (RIP1 & RIP2). Hierarchical routing protocols (BGP).

Each protocol has its own algorithm to choose the best path.so number of network layer devices along with some the path like bandwidth, load, delay, cost and MTU.

ROUTING PROTOCOL

Why we need ROUTING PROTOCOLS

CLASSIFICATION OF ROUTING PROTOCOL

An administrator manually assigns the path from source to destination throughout the n to n devices.Advantage of static Only admin configure for this reason Security is good. No bandwidth No overheadDisadvantage of static No practical on large network Administrator must update all networks.

STATIC ROUTING PROTOCOL

Static topology and configure

How to configure router to router and output

Routing Information Protocol (RIP) is a dynamic protocol used to find the best route or path from end-to-end (source to destination) including metric/hop count algorithm.Characteristics of RIP

◦ Uses hop count metric◦ Supports 15 hop ◦ Add value is 120◦ Support classful networks.◦ Routing update after 30seconds

Routing Information Protocol (RIP)

Codding for R1R1>enableR1#config terminalR1(config)#router ripR1(config-router)#no auto summaryR1(config-router)#passive-interfacefa0/0R1(config-router)#network 10.0.0.0R1(config-router)#network 192.168.10R1(config-router)#exitR1(config)#router ripR1(config)#version 2R1(config)#exitR1#show running confinR1#show ip rip databasR1#show ip routeR1#show ip rip interface

Routing Information Protocol (RIP) with codding

Codding for R2R2>enableR2#config terminalR2(config)#router ripR2(config-router)#no auto summaryR2(config-router)#network 10.0.0.0R2(config-router)#exitR2(config)#router ripR2(config)#version 2R2(config)#exitR2#show running confinR2#show ip rip databasR2#show ip routeR2#show ip rip interface


Codding for R3R3>enableR3#config terminalR3(config)#router ripR3(config-router)#no auto summaryR3(config-router)#passive-

interfacefa0/0R3(config-router)#network 10.0.0.0R3(config-router)#network 192.168.30R3(config-router)#exitR3(config)#router ripR3(config)#version 2R3(config)#exitR3#show running configR3#show ip rip databaseR3#show ip routeR3#show ip rip interface


This protocol is one of a family of IP Routing protocols and is an Interior Gateway Protocol (IGP) for the Internet, used to distribute IP routing information throughout the whole network.The following are the characteristic of OSPF AD value is 110 Classless and hierarchical network VLSM and unlimited hop counts.

Open Shortest Path First

Codding for R1Shala>enableShala#configure terminalShala(config)#router ospf 100Shala(config-router)# passive- interface

fa0/0Shala(config-router)#network 10.1.1.0 0.0.0.3 area 0Shala(config-router)#network 192.168.10.0 0.0.0.255 area 0

Shala(config-router)#exitShala#show running configShala#show ip routeShala#show ip ospf databaseShala#show ip ospf interface

Open shortest path first with codding

Codding for R2 Aziza>enable Aziza#configure terminal Aziza (config)#router ospf 100 Aziza (config-router)#network 10.1.1.0 0.0.0.3 area 0 Aziza (config-router)#network 10.2.2.0 0.0.0.3 area 0 Aziza (config-router)#exit Aziza #show running config Aziza #show ip route Aziza #show ip ospf database Aziza #show ip ospf interface


Codding for R3 Jackson>enable Jackson #configure terminal Jackson (config)#router ospf 100 Jackson (config-router)# passive- interface fa0/0 Jackson (config-router)#network 10.2.2.0 0.0.0.3 area 0Jackson (config-router)#network 192.168.30.0 0.0.0.255 area 0 Jackson (config-router)#exit Jackson #show running config Jackson #show ip route Jackson #show ip ospf database Jackson #show ip ospf interface


Different between RIP AND OSPF

THANK YOU

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