Department of Computer Science
COMSATS UNIVERSITY ISLAMABAD
ATTOCK CAMPUS
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Data Communication and Computer Networks Lab Manual
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Data Communication and Computer Networks Lab Manual
Submission Form
DCCN Lab Manual
Course Name Data Communication and Computer Networks
Teacher Name Dr. Fahad
Sr .
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Name
Tooba Liaquat
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Irsa Shehzadi
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Fatima Jabeen
Reg. No
SP20-BCS009
SP20-BCS017
SP20-BCS002
Sp20-bcs-017@cuiatk.edu.pk
Sp20-bcs-002@cuiatk.edu.pk
Teacher’s Signature
Student’s Signature
*Teacher
Email ID
Sp20-bcs-009@cuiatk.edu.pk
Remarks:
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Data Communication and Computer Networks Lab Manual
Acknowledgements
In the Name of Allah, the Most Beneficent, the Most Merciful.
Initially, we would like to Thank ALLAH Almighty who provides all the resources of
every kind to us, so that we make their proper use for benefit of mankind. May he keep
providing us with all the resources, and the guidance to keep helping the humanity.
We would like to express our sincere Thankful and Grateful to our teacher Mr. Waseem
Khan for providing us with all sorts of basic ideas and techniques essential for carrying
out this project work from the very beginning to the end and enabled us to present this
dissertation in this form. We are very much grateful to the COMSATS University
Islamabad, Attock Campus for providing us an enthusiastic support and opportunity.
PREFACE
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Data Communication and Computer Networks Lab Manual
This lab manual has been prepared to facilitate the students of computer
science in studying and analyzing various functions of a computer network. The
students will have plan the IP address scheme, configure and test the several network
devices. Different tools are used to monitor network traffic and analyses packets. The
lab sessions are designed to improve the abilities of the students by giving hands on
experience. After completing the laboratory exercises, the students will be familiar
with the practical issues of the different concepts explained in the course, as well as
with the real equipment used nowadays in computer networks.
PREPARED BY
Lab manual is prepared by Ms. Tooba Liaquat, Ms. Irsa Shehzadi and Ms. Fatima
Jabeen under the supervision of Dr. Fahad.
Lab 1
How to install Packet Tracer and sending packet from one PC to other:
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Data Communication and Computer Networks Lab Manual
From end devices select a PC drag to screen and drop there, named PC0 by default
By using same End devices drag another PC name with PC1
click on PC0 and this menu will
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Figure 1 Establish a connection between both PCs by using a cross table that is selected by default
in Desktop select IP Configuration for IP address
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enter IP address which is here 192.168.1.1 and subnet mask will automatically be generated by clicking on that
space
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Select command prompt, ping device PC1.
Enter ping command and provide it the Ip address of PC1 to ping it and then it shows the detail.
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Data Communication and Computer Networks Lab Manual
Select message packet and give it to PC0 and PC1.
This message shows the successful connection and sending of message from PC0 to PC1.
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Lab 2
CONNECT TWO NETWORKS AND ANALYZE TRAFFIC:
Task 01: Checking traffic in same network
1). Create two switched-Networks (two switches connected to each other and each
having PCs attached to them) in Packet Tracer. All PCs in both switches belong to the
same network ID. Data in one switched network can move inside that network and to
other switched-network also.
1). Observe the intelligence of switches. Observe that packets sent to other networks when
sent first time are broadcasted but next time uni-casted.
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Data Communication and Computer Networks Lab Manual
2)Observe Broadcast and Collision domains in the above Packet Tracer simulation.
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3)Repeat ‘show mac’ command to verify the contents of MAC address tables of switches to
build your understanding.
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Lab 3
Creating TWO switched networks (LANs) and connecting them together. LANS
have different Network IDs.
Figure 1
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Every PC of network A is assigned with IP address from PC1 192.168.100.1 to PC6
192.168.100.3 and MAC addresses and every PC of network B is assigned with IP address from
192.168.200.1 to 192.168.200.3 and MAC addresses.
Both switches are labeled with port numbers.
Two switches, switch0 and switch1 connected with port Fa0/4.
Switch0 relates to PC1 through Fa0/1, PC2 through Fa0/2 and PC3 through Fa0/3.
Switch1 relates to PC4 through Fa0/1, PC5 through Fa0/2 and PC6 through Fa0/3.
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Data Communication and Computer Networks Lab Manual
Figure 2
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PC 192.168.100.1 wants to send data to PC 192.168.200.3 - The packet is dropped at the
sender because the default gateway of PC 192.168.100.1 is not set.
When a PC belonging to Network A wants to communicate with another PC which is
part of Network B then we must mention in the sending PC, the IP address of Default
Gateway.
By specifying default gateway IP address, we mean that our requests for PCs in other
networks will first go to Default Gateway which will search the network in its list of networks
and after finding NetID, packet will be sent to the destination PC.
Figure 3
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Let’s set default gateway IP of PC 192.168.100.1 as 192.168.100.4
In this case, although IP of default gateway has been mentioned but the default gateway
machine does not physically exist between NetID 192.168.100.0 and NetID 192.168.200.0.
As show in the figure on the next page.
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Figure 4
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After setting the default gateway, PC 192.168.100.1 again sends packet to PC 192.168.200.3.
PC 192.168.100.2 and PC 192.168.100.3 drop it, while Switch1 rebroadcasts it to all its
up and running ports.
Repeating Lab 2 task 2 by adding a Router in between the switched network
.
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Data Communication and Computer Networks Lab Manual
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Assign default gateway IP addresses to both port of router which are linked with both
networks A to fa0/0 (192.168.100.4) and B to fa0/1 (192.168.200.4).
Also assign this default gateway IP address to all PCs of network A 192.168.100.4
And assign this default gateway IP address to all PCs of network B 192.168.200.4
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Data Communication and Computer Networks Lab Manual
Lab 4
How we set date and time in configuration modes:
We just add hostname as: Fatima Ali on configuration mode.
Set date and time
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Data Communication and Computer Networks Lab Manual
Banner with “Welcome it’s Fatima Ali”
Set enables and secret password
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Configuration line command( line console 0)
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Lab 5
WIRE SHARK(PACKET SNIFFING):
After starting Wireshark, do the following:
 Select Capture | Interfaces
 Select the interface on which packets need to be captured. This will usually be the
interface where the Packet/s column is constantly changing, which would indicate the
presence of live traffic). If you have multiple network interface cards (i.e. LAN card and
Wi-Fi adapter) you may need to check with your IT administrator to determine the right
interface.
 I double click on Wi-Fi because I am using Wi-Fi currently.
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Recreate the problem. The capture dialog should show the number of packets increasing.
Try to avoid running any other internet applications while capturing, closing other
browsers, Instant messengers etc.
Once the problem which is to be analysed has been reproduced, click on Stop. It may
take a few seconds for Wireshark to display the packets captured.
Save the packet trace in the default format. Click on the File menu option and select
Save As. By default, Wireshark will save the packet trace in Libecap format. This is a
filename with a. pcap extension.
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Select any of packet of your own choice to see its detail.
I selected UDP protocol and here is the detail of packet.
In ethernet section it gives the detail about source and destination of end devices.
In internet protocol section it gives detail about network layer.

The user data gram protocols are in transort layer it gives the detail about transmission of
packet either in TCP or UDP protocol.
The data section contain the detail about network layer and provide the detail about IP
address.
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Lab 6
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STATIC AND DYNAMIC CODE BINDING:
connect pc with switch
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Lab 7
IMAGE CHANGE:
We connect 2 different networks with router. Assign IP addresses to each PC and default gateways.
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Data Communication and Computer Networks Lab Manual
Also assign the gateway to the port of router.
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Add a server to the 2nd network.
Here is already existed image file.
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Created a file with name Fatima.html.
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Do the following code in the file and add a picture from your PC.
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Here is new added picture.
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Lab 8
Implementation of FTP Protocol
Figure:
Create a following network by combining 2 different networks with routers Assign IP
addresses and default gateway to each PC and server in the networks.
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Assign default gate way to both ports of router.
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On the server open the services section, in the services section go to FTP section, and assign
username and password and allow permissions such as read, write, delete, rename, list and
then add.
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Go to any PC, open command prompt, use command ftp 192.168.1.4 . Give username and
password and login.
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Now use different commands:
Dir for all directories files information.
? for help and all commands.
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Use get command for downloading file.
Create a file on any PC in the text editor and save it with .txt extension.
Use put command to upload a file using syntax put filename.extension.
Use can see the file is uploaded in directory with name DCCN.txt.
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Rename file using the command rename oldfilename newfilename.
You can see the file DCCN.txt is now rename as OOP.txt.
Use pwd command to print working directory.
Currently I am working in ftp directory.
Use cd command to change the current directory using syntax cd dirname
I changed my directory from ftp to http.
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Use help command to get all commands and any help regarding commands.
Use passive command to change the mode of protocol. It is a command to the FTP server
requesting a high order port for data transfer. A passive transfer is one in which the FTP data over
these high order ports while control is maintained in the lower ports.
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Now login in any PC of 2nd network and use dir command to check the file is available to other
users also that we have uploaded in the network 1.
Now the user xyz want to delete file but it can’t because we only provide it read write and list
permission.
Now the user abc want to delete file and it can because we provide it all permissions.
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Lab 9
Implementation of DNS and HTTP Protocol
Figure:
Create a following network by combining 2 different networks with routers.
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Assign each PC the IP address, default gateway, DNS server IP address to both networks.
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Assign each Server the IP address and default gateway.
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IN both servers google and facebook, go to the services HTTP, edit index file with the title name
FaceBook.
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Go to the DNS server, in the services section, go to the DNS section turn on DNS service and add
both servers google and Facebook by adding name and Ip address.
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Now go to any PC in the browser search by name as follows www.facebook.com and go.
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Lab 10
Implementation of Gmail using Email Protocol
Create a topology using 2 different network Ips. Assign IP address to each PC and servers.
Also assign default gateway to both port of routers and also to each PC and servers.
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Data Communication and Computer Networks Lab Manual
Assign IP address and default gateway and DNS server address to each PC.
On the DNS server using DNS protocol add IP address and name of Gmail.
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On the Gmail server using Email service add two different users along with their passwords also assign
domain name.
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Go to any PC, in the email section configure mail, by assigning email addresses and username password.
Also assign incoming and outgoing mail server.
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Now compose a mail by sending a mail from azka to Tooba.
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