36 CHAPTER 5
SIMULATION RESULT
In order to have a better network traffic system run in the PT. Bukit Makmur Mandiri
Utama, the author has designed some system that can be implemented in the company.
As the current network system in BUMA has no VLAN, which means that less security
and high broadcast traffic; the author intended to use VLAN, because it is important in
the company to keep the security in each department and to have better network
performance. Author will prove that the new design will have a better result than the
current system. Because of the project is for giving PT. Bukit Makmur Mandiri Utama a
network traffic solution and it is not yet granted by the company itself, the author cannot
add switch by author’s will and cannot change the system in the company, that is why
author choose to have a simulation. Author did a simulation using a Packet Tracer by
made a topology similar with the current topology. The meaning of similar that, author
did not use as many Personal Computer (host / PC) as in the real situation of the
company, but author made it as a parable.
The meaning of parable in the simulation to pretend that:
•
45 - 50 users = 5 users
•
35 - 44 users = 4 users
•
25 - 34 users = 3 users
•
15 - 24 users = 2 users
•
< 15 users = 1 user
37 The reason why author have to pretend the number of personal computer because, it is a
simulation that pretend to be the real system, the system cannot be run using an
application because it is simulated in Packet Tracer, and the look can be so messy if
keep using the real number of Personal Computers in the company. The Simulation is to
do comparison between the current network systems and the design made by author that
use of VLAN implementation and the addition of clustering switch in the PT. Bukit
Makmur Mandiri Utama Network System.
5.1
Simulation Process
As mentioned above that the simulation is being used to simulate the current
network system and the “designed” system. The designed term is the solution
design that author has made. The application that is used for simulation is
CISCO Packet Tracer.
In Packet Tracer, the type of devices has already
provided without need to install the IOS image of the device. There are three
types of devices that are used for simulation in Packet Tracer:
•
Core switch = 2960TT – 24
•
Distribution / Access switch = 2950TT – 24
•
Personal Computer = PC
All those devices will fill the network topology of PT. Bukit Makmur Mandiri
Utama network.
38 5.2
Current Network
The current network of BUMA has no VLAN, so every device in all departments
connects with others. Here is the simulation topology of the current network:
Figure 5.1 Simulation of current network system
IP Address: 192.168.12.11 – 192.168.12.61
The simulation in here represents the current network system in BUMA like in
figure 3.2. In the context of conceptual switch, switch A and switch B are being
the core switch that is connected to the distribution switch. The switch E in here
become a distribution switch and distribute the packet to the switch below it,
which is switch L, switch R, and switch H. The switch M connected to switch L
and switch I connected to switch H.
It can become a problem in the
performance, because there are too many hops for switch M and switch I that
39 they have to pass through switch L and switch H to get access to switch E and
then to switch B; too many hops means less performance.
Each switch representing each division, except for switch G, Y, I and switch O,
P, Q and switch V, W that handle 1 division. In here, all devices use a same
network of IP Address and they connect with others, so less security in the
system because, nobody knows if there is an inside intruders in the company that
can use some application to sniff and look around the data in other division.
High broadcast traffic can occurred because each node broadcasting to others,
there is no broadcast domain. The real data can be seen in the figure 3.3.
5.3
VLAN Simulation
Author has designed the VLAN topology like in the figure 4.4 that there are 3
clustering core switches, which are switch A, switch B, and switch E. The
distribution switches that connected will follow them to the ports of switch.
Here is the VLAN topology that is simulated using Packet Tracer:
Figure 5.2 VLAN Simulation
40 Figure 5.3 Show VLAN Brief (Switch A)
Figure 5.4 Show VLAN Brief (Switch B)
41 Figure 5.5 Show VLAN Brief (Switch E)
In the Figure 5.2 above, there is only core switch and distribution switch, this
design minimize the number of hops that previously occurs in the existing
system of the Switch E to improve the performance of the traffic. The VLAN
that has been configured makes no division can have connection to other
divisions, in other words no connection in every division that makes the security
inside the network system more secure. With VLAN implemented, it will helps
administrator to manage the broadcast domains, no high broadcast traffic in the
network traffic that previously dominate the total traffic in BUMA.
5.4
Discussion of the Result
After the topology has been designed and put into the Packet Tracer. The author
configured the workstation/devices into a right configuration; one with no VLAN
and just connecting all devices and one with VLAN and clustering switch. All
the devices has been configured correctly, except for the clustering switch.
Simulation using Packet Tracer has some limitation that need to be faced. In
Packet Tracer, author cannot configure the clustering switch because of the type
42 of switch available not supported clustering. The unsupported switch because of
clustering need higher version of Cisco Catalyst, which is 3500XL while in the
packet tracer, the highest version of the available switch is 2960TT; that is why
the clustering cannot be simulated.
First thing that is done to measure the speed of connection of other device in
Packet Tracer by using ping. Author choose the PC32 to ping PC36 because,
they are in the same IT VLAN and to have a comparison between the ping based
on figure 5.1 and figure 5.2 The command to do the ping in here is: “ping –t ip
address". Here are the screenshots of ping from PC32 to PC36:
Figure 5.6 Ping in the existing network
43 Figure 5.7 Ping in the VLAN network
The result of statistic can be seen that ping in the VLAN network is faster than
ping in the existing network, which means that VLAN improve the performance
of the network traffic [21].
5.4.1 Fault If Condition
In this fault if condition, author will test the benefit of using clustering switch,
that can back up the work of other switch if one switch is fail or overload or goes
down [22]. To simulate this condition, author made a new topology, because
there is no clustering and it is made like a mesh topology, because the concept of
work quite same between the use of mesh topology and clustering switch, even
though in real life, clustering switch does not need a mesh topology.
44 Author will use six switches and four PCs to simplify the testing, because the
purpose of this simulation just to see how fast that the link can goes back up. If
author used the topology in figure 5.2, the topology can be so mesh up and it will
be hard to be seen and so complex. That is the reason of just choose a simple
topology to test the clustering (mesh).
Figure 5.8 Pretend to be clustering
In the figure above, both switch 5 and switch 6 have 2 VLAN, which are VLAN
10 and VLAN 20. The way it was simulated to test the fault if condition that
author will cut the switch one by one and let see in the ping, how the packet will
react if there is a switch off. The simulation has captured that the route that has
been determined by default that when PC 1 want to go to PC 3 is through switch
5 – switch 2 – switch 3 – switch 6. The route has been determined by default
when PC1 has sent ARP packet to all nodes to determine the link and test how it
will reroute and the time it takes to tell the other nodes about what happen and
try to find a new route back.
45 First fault condition:
In this first fault condition, switch 2 is cut to simulate how the packets will react
with the sudden lost connection to switch 2.
Figure 5.9 Switch 2 cut
Figure 5.10 The ping response
46 Second fault condition:
In this second fault condition, switch 1 that is cut to see how the packets will
react with the lost connection to switch 1.
Figure 5.11 Switch 1 cut
Figure 5.12 Response of switch 1 cut
47 Third fault condition:
In this third fault condition, switch 3 that is cut to see how the packets will react
with the lost connection to switch 3.
Figure 5.13 Switch 3 cut
Figure 5.14 The response of switch 3 cut
48 Fourth Fault Condition:
In this fourth fault condition, switch 4 that is cut to see how the packets will react
with the lost connection to switch 4.
Figure 5.15 Switch 4 Cut
Figure 5.16 The Reply of ping
49 Fifth Fault Condition
In this fifth fault condition, switch 1 and switch 4 are cut to see how the packets
will react with the lost connection to switch 1 and switch 4.
Figure 5.17 Switch 1 and Switch 4 are cut
Figure 5.18 The result of switch 1 and switch 4 cut
50 Sixth Fault Condition
In this sixth fault condition, switch 2 and switch 3 are cut to see how the packets
will react with the lost connection to switch 2 and switch 3. Switch 2 and switch
3 is the determined path from PC 1 to PC 3.
Figure 5.19 Switch 2 and Switch 3 are cut
Figure 5.20 The result of switch 2 and switch 3 cut
51 Seventh Fault Condition
In this fifth fault condition, switch 2 and switch 4 are cut to see how the packets
will react with the lost connection to switch 2, then lost connection to switch 4.
Figure 5.21 Switch 2 and switch 4 are cut
Figure 5.22 The result of switch 2 and switch 4 cut