routing protocals

1.  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.

2.  After opening Opnet simulator, the topology was designed
for the first scenario and named HubOnly:
Hub Only
 Specifying the Attributes of the Topology

3.  The Topology:

4.  Configuring the nodes
The 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.

5.  Choosing Statistics
The 4 individual statistics were
chosen which are Delay, Traffic
Received (packets/sec), Traffic
sent (packets/sec) and collision
count as shown below:
 Configuring the simulation
The simulation was configured
as stated in the guideline and
the simulation time was put as 2
mins as shown below:

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

7.  Result
After 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)

8.  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

9.  Collision Count
• Packets Sent

10. 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.

11. 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.

12. • SwitchANDSwitch• A new Scenario: A Scenario for SwitchOnly

13. 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.

14.  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.

15. 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.

16. 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.

19. 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 overhead
Disadvantage of static
 No practical on large network
 Administrator must update all networks.

22. 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

23. Codding for R1
R1>enable
R1#config terminal
R1(config)#router rip
R1(config-router)#no auto summary
R1(config-router)#passive-interfacefa0/0
R1(config-router)#network 10.0.0.0
R1(config-router)#network 192.168.10
R1(config-router)#exit
R1(config)#router rip
R1(config)#version 2
R1(config)#exit
R1#show running confin
R1#show ip rip databas
R1#show ip route
R1#show ip rip interface

24. Codding for R2
R2>enable
R2#config terminal
R2(config)#router rip
R2(config-router)#no auto summary
R2(config-router)#network 10.0.0.0
R2(config-router)#exit
R2(config)#router rip
R2(config)#version 2
R2(config)#exit
R2#show running confin
R2#show ip rip databas
R2#show ip route
R2#show ip rip interface

25. Codding for R3
R3>enable
R3#config terminal
R3(config)#router rip
R3(config-router)#no auto summary
R3(config-router)#passive-
interfacefa0/0
R3(config-router)#network 10.0.0.0
R3(config-router)#network
192.168.30
R3(config-router)#exit
R3(config)#router rip
R3(config)#version 2
R3(config)#exit
R3#show running config
R3#show ip rip database
R3#show ip route
R3#show ip rip interface

26. 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.

27. Codding for R1
Shala>enable
Shala#configure terminal
Shala(config)#router ospf 100
Shala(config-router)# passive- interface
fa0/0
Shala(config-router)#network 10.1.1.0 0.0.0.3
area 0
Shala(config-router)#network 192.168.10.0
0.0.0.255 area 0
Shala(config-router)#exit
Shala#show running config
Shala#show ip route
Shala#show ip ospf database
Shala#show ip ospf interface

28. 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

29. 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 0
Jackson (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