[Solved] Computer Science Assignment2 CC

Assignment Prompt & Instructions

– 2 years ago

**files (6)**

– ## Assignment2_Winter_2025_MSIT_650_Networking_Project2.pdf

– ## Wireshark_SSL_Sept_15_2009.pdf

– ## Wireshark_IP_Sept_15_2009.pdf

– WiresharkExercises.pdf
– Wireshark_HTTP_Sept_15_2009.pdf
– WiresharkQuickStartGuide.pdf

**## Assignment2_Winter_2025_MSIT_650_Networking_Project2.pdf**

Nova Southeastern University

College of Engineering and Computing

Winter 2025 – Master Level Course

Term Code: 202530 – CRN: 30675 Sec: L01 Cr: 3.0

Dates: 8 weeks: 01/06/2025 – 03/02/2025

MSIT 650 Platform and Network Tech (3 Credits)

Assignment 2

Please refer to the course calendar and syllabus for assignment due date

and assignment grade percentage.

Your documents must be submitted before the due date on the proper

blackboard assignment number (assignment 2)

Your document for this project will be submitted to BlackBoard

(Assignment 2) in one of the following file formats: ASCII, MS Word,

PDF, or Compressed (ZIP).

Assignment 2:

This assignment will involve you using a tool called Wireshark, it works

on almost all operating systems. This is a powerful tool that can be used

to explore networking.

The link is:

http://www.wireshark.org/download.html

The assignment provides a quick start guide to help you get started and

involves completing 5 basic exercises and then 3 specific exercises which

include HTTP, IP and SSL, for a total of eight exercises.

1) Wireshark Exercises (this includes 5 exercises to help get started)

2) WiresharK_HTTP

3) Wireshark_IP

4) Wireshark_SSL

The exercises are self-explanatory, and you only need to carefully follow

the steps provided by each exercise.

If you even remotely do not understand the assignment, please email me

and I will try to clarify further.

Note:

The exercises are based around a book: Computer Networking: A Top

down Approach, 5th edition by J.F. Kurose, K.W Ross.

This book is not necessary but might be helpful although may provide far

more detail than necessary to complete the assignment.

[http://www.wireshark.org/download.html](http://www.wireshark.org/download.html)

Between YouTube and the Internet there are numerous examples on

Wireshark, use these as guides.

Regards

Dr. Kane

**## Wireshark_SSL_Sept_15_2009.pdf**

Wireshark Lab: SSL

Version: 2.0
© 2009 J.F. Kurose, K.W. Ross. All Rights Reserved

Computer Networking: A Top-
down Approach, 5th edition.

In this lab, we’ll investigate the Secure Sockets Layer (SSL) protocol, focusing on the
SSL records sent over a TCP connection. We’ll do so by analyzing a trace of the SSL
records sent between your host and an e-commerce server. We’ll investigate the various
SSL record types as well as the fields in the SSL messages.

1. Capturing packets in an SSL session

The first step is to capture the packets in an SSL session. To do this, you should go to
your favorite e-commerce site and begin the process of purchasing an item (but
terminating before making the actual purpose!). After capturing the packets with
Wireshark, you should set the filter so that it displays only the Ethernet frames that
contain SSL records sent from and received by your host. (An SSL record is the same
thing as an SSL message.) You should obtain something like screenshot on the previous
page.

If you have difficulty creating a trace, you should download the zip file
http://gaia.cs.umass.edu/wireshark-labs/wireshark-traces.zip and extract the ssl-ethereal-
trace-1 packet trace.

2. A look at the captured trace

Your Wireshark GUI should be displaying only the Ethernet frames that have SSL
records. It is important to keep in mind that an Ethernet frame may contain one or more
SSL records. (This is very different from HTTP, for which each frame contains either one
complete HTTP message or a portion of a HTTP message.) Also, an SSL record may not
completely fit into an Ethernet frame, in which case multiple frames will be needed to
carry the record.

1. For each of the first 8 Ethernet frames, specify the source of the frame (client or
server), determine the number of SSL records that are included in the frame, and
list the SSL record types that are included in the frame. Draw a timing diagram
between client and server, with one arrow for each SSL record.

2. Each of the SSL records begins with the same three fields (with possibly different
values). One of these fields is “content type” and has length of one byte. List all
three fields and their lengths.

ClientHello Record:

3. Expand the ClientHello record. (If your trace contains multiple ClientHello
records, expand the frame that contains the first one.) What is the value of the
content type?

4. Does the ClientHello record contain a nonce (also known as a “challenge”)? If so,
what is the value of the challenge in hexadecimal notation?

5. Does the ClientHello record advertise the cyber suites it supports? If so, in the
first listed suite, what are the public-key algorithm, the symmetric-key algorithm,
and the hash algorithm?

ServerHello Record:

6. Locate the ServerHello SSL record. Does this record specify a chosen cipher
suite? What are the algorithms in the chosen cipher suite?

7. Does this record include a nonce? If so, how long is it? What is the purpose of the
client and server nonces in SSL?

8. Does this record include a session ID? What is the purpose of the session ID?
9. Does this record contain a certificate, or is the certificate included in a separate

record. Does the certificate fit into a single Ethernet frame?

Client Key Exchange Record:

10. Locate the client key exchange record. Does this record contain a pre-master
secret? What is this secret used for? Is the secret encrypted? If so, how? How long
is the encrypted secret?

Change Cipher Spec Record (sent by client) and Encrypted Handshake Record:

11. What is the purpose of the Change Cipher Spec record? How many bytes is the
record in your trace?

12. In the encrypted handshake record, what is being encrypted? How?
13. Does the server also send a change cipher record and an encrypted handshake

record to the client? How are those records different from those sent by the client?

Application Data

14. How is the application data being encrypted? Do the records containing
application data include a MAC? Does Wireshark distinguish between the
encrypted application data and the MAC?

15. Comment on and explain anything else that you found interesting in the trace.

**## Wireshark_IP_Sept_15_2009.pdf**

Wireshark Lab: IP

Version: 2.0
© 2009 J.F. Kurose, K.W. Ross. All Rights Reserved

Computer Networking: A Top-
down Approach, 5th edition.

In this lab, we’ll investigate the IP protocol, focusing on the IP datagram. We’ll do so by
analyzing a trace of IP datagrams sent and received by an execution of the traceroute
program (the traceroute program itself is explored in more detail in the Wireshark
ICMP lab). We’ll investigate the various fields in the IP datagram, and study IP
fragmentation in detail.

Before beginning this lab, you’ll probably want to review sections 1.4.3 in the text and
section 3.4 of RFC 2151 [ftp://ftp.rfc-editor.org/in-notes/rfc2151.txt] to update yourself
on the operation of the traceroute program. You’ll also want to read Section 4.4 in
the text, and probably also have RFC 791 [ftp://ftp.rfc-editor.org/in-notes/rfc791.txt] on
hand as well, for a discussion of the IP protocol.1

1. Capturing packets from an execution of traceroute

In order to generate a trace of IP datagrams for this lab, we’ll use the traceroute
program to send datagrams of different sizes towards some destination, X. Recall that
traceroute operates by first sending one or more datagrams with the time-to-live
(TTL) field in the IP header set to 1; it then sends a series of one or more datagrams
towards the same destination with a TTL value of 2; it then sends a series of datagrams
towards the same destination with a TTL value of 3; and so on. Recall that a router must
decrement the TTL in each received datagram by 1 (actually, RFC 791 says that the
router must decrement the TTL by at least one). If the TTL reaches 0, the router returns
an ICMP message (type 11 – TTL-exceeded) to the sending host. As a result of this
behavior, a datagram with a TTL of 1 (sent by the host executing traceroute) will
cause the router one hop away from the sender to send an ICMP TTL-exceeded message
back to the sender; the datagram sent with a TTL of 2 will cause the router two hops
away to send an ICMP message back to the sender; the datagram sent with a TTL of 3

1 All references to the text in this lab are to Computer Networking: A Top-down Approach, 5th edition.

will cause the router three hops away to send an ICMP message back to the sender; and
so on. In this manner, the host executing traceroute can learn the identities of the
routers between itself and destination X by looking at the source IP addresses in the
datagrams containing the ICMP TTL-exceeded messages.

We’ll want to run traceroute and have it send datagrams of various lengths.

 Windows. The tracert program (used for our ICMP Wireshark lab) provided
with Windows does not allow one to change the size of the ICMP echo request
(ping) message sent by the tracert program. A nicer Windows traceroute
program is pingplotter, available both in free version and shareware versions at
http://www.pingplotter.com. Download and install pingplotter, and test it out by
performing a few traceroutes to your favorite sites. The size of the ICMP echo
request message can be explicitly set in pingplotter by selecting the menu item
Edit-> Options->Packet Options and then filling in the Packet Size field. The
default packet size is 56 bytes. Once pingplotter has sent a series of packets with
the increasing TTL values, it restarts the sending process again with a TTL of 1,
after waiting Trace Interval amount of time. The value of Trace Interval and the
number of intervals can be explicitly set in pingplotter.

 Linux/Unix. With the Unix traceroute command, the size of the UDP
datagram sent towards the destination can be explicitly set by indicating the
number of bytes in the datagram; this value is entered in the traceroute
command line immediately after the name or address of the destination. For
example, to send traceroute datagrams of 2000 bytes towards
gaia.cs.umass.edu, the command would be:

%traceroute gaia.cs.umass.edu 2000

Do the following:

 Start up Wireshark and begin packet capture (Capture->Start) and then press OK
on the Wireshark Packet Capture Options screen (we’ll not need to select any
options here).

 If you are using a Windows platform, start up pingplotter and enter the name of a
target destination in the “Address to Trace Window.” Enter 3 in the “# of times to
Trace” field, so you don’t gather too much data. Select the menu item Edit-
>Advanced Options->Packet Options and enter a value of 56 in the Packet Size
field and then press OK. Then press the Trace button. You should see a
pingplotter window that looks something like this:

Next, send a set of datagrams with a longer length, by selecting Edit->Advanced
Options->Packet Options and enter a value of 2000 in the Packet Size field and
then press OK. Then press the Resume button.

Finally, send a set of datagrams with a longer length, by selecting Edit-
>Advanced Options->Packet Options and enter a value of 3500 in the Packet Size
field and then press OK. Then press the Resume button.

Stop Wireshark tracing.

 If you are using a Unix platform, enter three traceroute commands, one with

a length of 56 bytes, one with a length of 2000 bytes, and one with a length of
3500 bytes.

Stop Wireshark tracing.

If you are unable to run Wireshark on a live network connection, you can download a
packet trace file that was captured while following the steps above on one of the author’s
Windows computers2. You may well find it valuable to download this trace even if
you’ve captured your own trace and use it, as well as your own trace, when you explore
the questions below.

2 Download the zip file http://gaia.cs.umass.edu/wireshark-labs/wireshark-traces.zip and extract the file ip-
ethereal-trace-1. The traces in this zip file were collected by Wireshark running on one of the author’s
computers, while performing the steps indicated in the Wireshark lab. Once you have downloaded the
trace, you can load it into Wireshark and view the trace using the File pull down menu, choosing Open, and
then selecting the ip-ethereal-trace-1 trace file.

2. A look at the captured trace

In your trace, you should be able to see the series of ICMP Echo Request (in the case of
Windows machine) or the UDP segment (in the case of Unix) sent by your computer and
the ICMP TTL-exceeded messages returned to your computer by the intermediate
routers. In the questions below, we’ll assume you are using a Windows machine; the
corresponding questions for the case of a Unix machine should be clear. Whenever
possible, when answering a question you should hand in a printout of the packet(s) within
the trace that you used to answer the question asked. Annotate the printout to explain
your answer. To print a packet, use File->Print, choose Selected packet only, choose
Packet summary line, and select the minimum amount of packet detail that you need to
answer the question.

1. Select the first ICMP Echo Request message sent by your computer, and expand
the Internet Protocol part of the packet in the packet details window.

What is the IP address of your computer?

2. Within the IP packet header, what is the value in the upper layer protocol field?
3. How many bytes are in the IP header? How many bytes are in the payload of the

IP datagram? Explain how you determined the number of payload bytes.
4. Has this IP datagram been fragmented? Explain how you determined whether or

not the datagram has been fragmented.

Next, sort the traced packets according to IP source address by clicking on the Source
column header; a small downward pointing arrow should appear next to the word Source.
If the arrow points up, click on the Source column header again. Select the first ICMP
Echo Request message sent by your computer, and expand the Internet Protocol portion
in the “details of selected packet header” window. In the “listing of captured packets”
window, you should see all of the subsequent ICMP messages (perhaps with additional
interspersed packets sent my other protocols running on your computer) below this first
ICMP. Use the down arrow to move through the ICMP messages sent by your computer.

5. Which fields in the IP datagram always change from one datagram to the next
within this series of ICMP messages sent by your computer?

6. Which fields stay constant? Which of the fields must stay constant? Which fields
must change? Why?

7. Describe the pattern you see in the values in the Identification field of the IP
datagram

Next (with the packets still sorted by source address) find the series of ICMP TTL-
exceeded replies sent to your computer by the nearest (first hop) router.

8. What is the value in the Identification field and the TTL field?
9. Do these values remain unchanged for all of the ICMP TTL-exceeded replies sent

to your computer by the nearest (first hop) router? Why?

Fragmentation

Sort the packet listing according to time again by clicking on the Time column.

10. Find the first ICMP Echo Request message that was sent by your computer after
you changed the Packet Size in pingplotter to be 2000. Has that message been
fragmented across more than one IP datagram? [Note: if you find your packet has
not been fragmented, you should download the zip file
http://gaia.cs.umass.edu/wireshark-labs/wireshark-traces.zip and extract the ip-
ethereal-trace-1packet trace. If your computer has an Ethernet interface, a packet
size of 2000 should cause fragmentation.3]

11. Print out the first fragment of the fragmented IP datagram. What information in
the IP header indicates that the datagram been fragmented? What information in
the IP header indicates whether this is the first fragment versus a latter fragment?
How long is this IP datagram?

3 The packets in the ip-ethereal-trace-1 trace file in http://gaia.cs.umass.edu/wireshark-labs/wireshark-
traces.zip are all less that 1500 bytes. This is because the computer on which the trace was gathered has an
Ethernet card that limits the length of the maximum IP packet to 1500 bytes (40 bytes of TCP/IP header
data and 1460 bytes of upper-layer protocol payload). This 1500 byte value is the standard maximum
length allowed by Ethernet. If your trace indicates a datagram longer 1500 bytes, and your computer is
using an Ethernet connection, then Wireshark is reporting the wrong IP datagram length; it will likely also
show only one large IP datagram rather than multiple smaller datagrams.. This inconsistency in reported
lengths is due to the interaction between the Ethernet driver and the Wireshark software. We recommend
that if you have this inconsistency, that you perform this lab using the ip-ethereal-trace-1 trace file.

12. Print out the second fragment of the fragmented IP datagram. What information in
the IP header indicates that this is not the first datagram fragment? Are the more
fragments? How can you tell?

13. What fields change in the IP header between the first and second fragment?

Now find the first ICMP Echo Request message that was sent by your computer after you
changed the Packet Size in pingplotter to be 3500.

14. How many fragments were created from the original datagram?
15. What fields change in the IP header among the fragments?

**WiresharkExercises.pdf**

This file is too large to display. [View in new window](https://www.sweetstudy.com/files/wiresharkexercises-pdf)

**Wireshark_HTTP_Sept_15_2009.pdf**

This file is too large to display. [View in new window](https://www.sweetstudy.com/files/wireshark-http-sept-15-2009-pdf)

**WiresharkQuickStartGuide.pdf**

This file is too large to display. [View in new window](https://www.sweetstudy.com/files/wiresharkquickstartguide-pdf)

**WiresharkQuickStartGuide.pdf**

This file is too large to display. [View in new window](https://www.sweetstudy.com/files/wiresharkquickstartguide-pdf)

**## Assignment2_Winter_2025_MSIT_650_Networking_Project2.pdf**

Nova Southeastern University

College of Engineering and Computing

Winter 2025 – Master Level Course

Term Code: 202530 – CRN: 30675 Sec: L01 Cr: 3.0

Dates: 8 weeks: 01/06/2025 – 03/02/2025

MSIT 650 Platform and Network Tech (3 Credits)

Assignment 2

Please refer to the course calendar and syllabus for assignment due date

and assignment grade percentage.

Your documents must be submitted before the due date on the proper

blackboard assignment number (assignment 2)

Your document for this project will be submitted to BlackBoard

(Assignment 2) in one of the following file formats: ASCII, MS Word,

PDF, or Compressed (ZIP).

Assignment 2:

This assignment will involve you using a tool called Wireshark, it works

on almost all operating systems. This is a powerful tool that can be used

to explore networking.

The link is:

http://www.wireshark.org/download.html

The assignment provides a quick start guide to help you get started and

involves completing 5 basic exercises and then 3 specific exercises which

include HTTP, IP and SSL, for a total of eight exercises.

1) Wireshark Exercises (this includes 5 exercises to help get started)

2) WiresharK_HTTP

3) Wireshark_IP

4) Wireshark_SSL

The exercises are self-explanatory, and you only need to carefully follow

the steps provided by each exercise.

If you even remotely do not understand the assignment, please email me

and I will try to clarify further.

Note:

The exercises are based around a book: Computer Networking: A Top

down Approach, 5th edition by J.F. Kurose, K.W Ross.

This book is not necessary but might be helpful although may provide far

more detail than necessary to complete the assignment.

[http://www.wireshark.org/download.html](http://www.wireshark.org/download.html)

Between YouTube and the Internet there are numerous examples on

Wireshark, use these as guides.

Regards

Dr. Kane

**## Wireshark_SSL_Sept_15_2009.pdf**

Wireshark Lab: SSL

Version: 2.0
© 2009 J.F. Kurose, K.W. Ross. All Rights Reserved

Computer Networking: A Top-
down Approach, 5th edition.

In this lab, we’ll investigate the Secure Sockets Layer (SSL) protocol, focusing on the
SSL records sent over a TCP connection. We’ll do so by analyzing a trace of the SSL
records sent between your host and an e-commerce server. We’ll investigate the various
SSL record types as well as the fields in the SSL messages.

1. Capturing packets in an SSL session

The first step is to capture the packets in an SSL session. To do this, you should go to
your favorite e-commerce site and begin the process of purchasing an item (but
terminating before making the actual purpose!). After capturing the packets with
Wireshark, you should set the filter so that it displays only the Ethernet frames that
contain SSL records sent from and received by your host. (An SSL record is the same
thing as an SSL message.) You should obtain something like screenshot on the previous
page.

If you have difficulty creating a trace, you should download the zip file
http://gaia.cs.umass.edu/wireshark-labs/wireshark-traces.zip and extract the ssl-ethereal-
trace-1 packet trace.

2. A look at the captured trace

Your Wireshark GUI should be displaying only the Ethernet frames that have SSL
records. It is important to keep in mind that an Ethernet frame may contain one or more
SSL records. (This is very different from HTTP, for which each frame contains either one
complete HTTP message or a portion of a HTTP message.) Also, an SSL record may not
completely fit into an Ethernet frame, in which case multiple frames will be needed to
carry the record.

1. For each of the first 8 Ethernet frames, specify the source of the frame (client or
server), determine the number of SSL records that are included in the frame, and
list the SSL record types that are included in the frame. Draw a timing diagram
between client and server, with one arrow for each SSL record.

2. Each of the SSL records begins with the same three fields (with possibly different
values). One of these fields is “content type” and has length of one byte. List all
three fields and their lengths.

ClientHello Record:

3. Expand the ClientHello record. (If your trace contains multiple ClientHello
records, expand the frame that contains the first one.) What is the value of the
content type?

4. Does the ClientHello record contain a nonce (also known as a “challenge”)? If so,
what is the value of the challenge in hexadecimal notation?

5. Does the ClientHello record advertise the cyber suites it supports? If so, in the
first listed suite, what are the public-key algorithm, the symmetric-key algorithm,
and the hash algorithm?

ServerHello Record:

6. Locate the ServerHello SSL record. Does this record specify a chosen cipher
suite? What are the algorithms in the chosen cipher suite?

7. Does this record include a nonce? If so, how long is it? What is the purpose of the
client and server nonces in SSL?

8. Does this record include a session ID? What is the purpose of the session ID?
9. Does this record contain a certificate, or is the certificate included in a separate

record. Does the certificate fit into a single Ethernet frame?

Client Key Exchange Record:

10. Locate the client key exchange record. Does this record contain a pre-master
secret? What is this secret used for? Is the secret encrypted? If so, how? How long
is the encrypted secret?

Change Cipher Spec Record (sent by client) and Encrypted Handshake Record:

11. What is the purpose of the Change Cipher Spec record? How many bytes is the
record in your trace?

12. In the encrypted handshake record, what is being encrypted? How?
13. Does the server also send a change cipher record and an encrypted handshake

record to the client? How are those records different from those sent by the client?

Application Data

14. How is the application data being encrypted? Do the records containing
application data include a MAC? Does Wireshark distinguish between the
encrypted application data and the MAC?

15. Comment on and explain anything else that you found interesting in the trace.

**## Wireshark_IP_Sept_15_2009.pdf**

Wireshark Lab: IP

Version: 2.0
© 2009 J.F. Kurose, K.W. Ross. All Rights Reserved

Computer Networking: A Top-
down Approach, 5th edition.

In this lab, we’ll investigate the IP protocol, focusing on the IP datagram. We’ll do so by
analyzing a trace of IP datagrams sent and received by an execution of the traceroute
program (the traceroute program itself is explored in more detail in the Wireshark
ICMP lab). We’ll investigate the various fields in the IP datagram, and study IP
fragmentation in detail.

Before beginning this lab, you’ll probably want to review sections 1.4.3 in the text and
section 3.4 of RFC 2151 [ftp://ftp.rfc-editor.org/in-notes/rfc2151.txt] to update yourself
on the operation of the traceroute program. You’ll also want to read Section 4.4 in
the text, and probably also have RFC 791 [ftp://ftp.rfc-editor.org/in-notes/rfc791.txt] on
hand as well, for a discussion of the IP protocol.1

1. Capturing packets from an execution of traceroute

In order to generate a trace of IP datagrams for this lab, we’ll use the traceroute
program to send datagrams of different sizes towards some destination, X. Recall that
traceroute operates by first sending one or more datagrams with the time-to-live
(TTL) field in the IP header set to 1; it then sends a series of one or more datagrams
towards the same destination with a TTL value of 2; it then sends a series of datagrams
towards the same destination with a TTL value of 3; and so on. Recall that a router must
decrement the TTL in each received datagram by 1 (actually, RFC 791 says that the
router must decrement the TTL by at least one). If the TTL reaches 0, the router returns
an ICMP message (type 11 – TTL-exceeded) to the sending host. As a result of this
behavior, a datagram with a TTL of 1 (sent by the host executing traceroute) will
cause the router one hop away from the sender to send an ICMP TTL-exceeded message
back to the sender; the datagram sent with a TTL of 2 will cause the router two hops
away to send an ICMP message back to the sender; the datagram sent with a TTL of 3

1 All references to the text in this lab are to Computer Networking: A Top-down Approach, 5th edition.

will cause the router three hops away to send an ICMP message back to the sender; and
so on. In this manner, the host executing traceroute can learn the identities of the
routers between itself and destination X by looking at the source IP addresses in the
datagrams containing the ICMP TTL-exceeded messages.

We’ll want to run traceroute and have it send datagrams of various lengths.

 Windows. The tracert program (used for our ICMP Wireshark lab) provided
with Windows does not allow one to change the size of the ICMP echo request
(ping) message sent by the tracert program. A nicer Windows traceroute
program is pingplotter, available both in free version and shareware versions at
http://www.pingplotter.com. Download and install pingplotter, and test it out by
performing a few traceroutes to your favorite sites. The size of the ICMP echo
request message can be explicitly set in pingplotter by selecting the menu item
Edit-> Options->Packet Options and then filling in the Packet Size field. The
default packet size is 56 bytes. Once pingplotter has sent a series of packets with
the increasing TTL values, it restarts the sending process again with a TTL of 1,
after waiting Trace Interval amount of time. The value of Trace Interval and the
number of intervals can be explicitly set in pingplotter.

 Linux/Unix. With the Unix traceroute command, the size of the UDP
datagram sent towards the destination can be explicitly set by indicating the
number of bytes in the datagram; this value is entered in the traceroute
command line immediately after the name or address of the destination. For
example, to send traceroute datagrams of 2000 bytes towards
gaia.cs.umass.edu, the command would be:

%traceroute gaia.cs.umass.edu 2000

Do the following:

 Start up Wireshark and begin packet capture (Capture->Start) and then press OK
on the Wireshark Packet Capture Options screen (we’ll not need to select any
options here).

 If you are using a Windows platform, start up pingplotter and enter the name of a
target destination in the “Address to Trace Window.” Enter 3 in the “# of times to
Trace” field, so you don’t gather too much data. Select the menu item Edit-
>Advanced Options->Packet Options and enter a value of 56 in the Packet Size
field and then press OK. Then press the Trace button. You should see a
pingplotter window that looks something like this:

Next, send a set of datagrams with a longer length, by selecting Edit->Advanced
Options->Packet Options and enter a value of 2000 in the Packet Size field and
then press OK. Then press the Resume button.

Finally, send a set of datagrams with a longer length, by selecting Edit-
>Advanced Options->Packet Options and enter a value of 3500 in the Packet Size
field and then press OK. Then press the Resume button.

Stop Wireshark tracing.

 If you are using a Unix platform, enter three traceroute commands, one with

a length of 56 bytes, one with a length of 2000 bytes, and one with a length of
3500 bytes.

Stop Wireshark tracing.

If you are unable to run Wireshark on a live network connection, you can download a
packet trace file that was captured while following the steps above on one of the author’s
Windows computers2. You may well find it valuable to download this trace even if
you’ve captured your own trace and use it, as well as your own trace, when you explore
the questions below.

2 Download the zip file http://gaia.cs.umass.edu/wireshark-labs/wireshark-traces.zip and extract the file ip-
ethereal-trace-1. The traces in this zip file were collected by Wireshark running on one of the author’s
computers, while performing the steps indicated in the Wireshark lab. Once you have downloaded the
trace, you can load it into Wireshark and view the trace using the File pull down menu, choosing Open, and
then selecting the ip-ethereal-trace-1 trace file.

2. A look at the captured trace

In your trace, you should be able to see the series of ICMP Echo Request (in the case of
Windows machine) or the UDP segment (in the case of Unix) sent by your computer and
the ICMP TTL-exceeded messages returned to your computer by the intermediate
routers. In the questions below, we’ll assume you are using a Windows machine; the
corresponding questions for the case of a Unix machine should be clear. Whenever
possible, when answering a question you should hand in a printout of the packet(s) within
the trace that you used to answer the question asked. Annotate the printout to explain
your answer. To print a packet, use File->Print, choose Selected packet only, choose
Packet summary line, and select the minimum amount of packet detail that you need to
answer the question.

1. Select the first ICMP Echo Request message sent by your computer, and expand
the Internet Protocol part of the packet in the packet details window.

What is the IP address of your computer?

2. Within the IP packet header, what is the value in the upper layer protocol field?
3. How many bytes are in the IP header? How many bytes are in the payload of the

IP datagram? Explain how you determined the number of payload bytes.
4. Has this IP datagram been fragmented? Explain how you determined whether or

not the datagram has been fragmented.

Next, sort the traced packets according to IP source address by clicking on the Source
column header; a small downward pointing arrow should appear next to the word Source.
If the arrow points up, click on the Source column header again. Select the first ICMP
Echo Request message sent by your computer, and expand the Internet Protocol portion
in the “details of selected packet header” window. In the “listing of captured packets”
window, you should see all of the subsequent ICMP messages (perhaps with additional
interspersed packets sent my other protocols running on your computer) below this first
ICMP. Use the down arrow to move through the ICMP messages sent by your computer.

5. Which fields in the IP datagram always change from one datagram to the next
within this series of ICMP messages sent by your computer?

6. Which fields stay constant? Which of the fields must stay constant? Which fields
must change? Why?

7. Describe the pattern you see in the values in the Identification field of the IP
datagram

Next (with the packets still sorted by source address) find the series of ICMP TTL-
exceeded replies sent to your computer by the nearest (first hop) router.

8. What is the value in the Identification field and the TTL field?
9. Do these values remain unchanged for all of the ICMP TTL-exceeded replies sent

to your computer by the nearest (first hop) router? Why?

Fragmentation

Sort the packet listing according to time again by clicking on the Time column.

10. Find the first ICMP Echo Request message that was sent by your computer after
you changed the Packet Size in pingplotter to be 2000. Has that message been
fragmented across more than one IP datagram? [Note: if you find your packet has
not been fragmented, you should download the zip file
http://gaia.cs.umass.edu/wireshark-labs/wireshark-traces.zip and extract the ip-
ethereal-trace-1packet trace. If your computer has an Ethernet interface, a packet
size of 2000 should cause fragmentation.3]

11. Print out the first fragment of the fragmented IP datagram. What information in
the IP header indicates that the datagram been fragmented? What information in
the IP header indicates whether this is the first fragment versus a latter fragment?
How long is this IP datagram?

3 The packets in the ip-ethereal-trace-1 trace file in http://gaia.cs.umass.edu/wireshark-labs/wireshark-
traces.zip are all less that 1500 bytes. This is because the computer on which the trace was gathered has an
Ethernet card that limits the length of the maximum IP packet to 1500 bytes (40 bytes of TCP/IP header
data and 1460 bytes of upper-layer protocol payload). This 1500 byte value is the standard maximum
length allowed by Ethernet. If your trace indicates a datagram longer 1500 bytes, and your computer is
using an Ethernet connection, then Wireshark is reporting the wrong IP datagram length; it will likely also
show only one large IP datagram rather than multiple smaller datagrams.. This inconsistency in reported
lengths is due to the interaction between the Ethernet driver and the Wireshark software. We recommend
that if you have this inconsistency, that you perform this lab using the ip-ethereal-trace-1 trace file.

12. Print out the second fragment of the fragmented IP datagram. What information in
the IP header indicates that this is not the first datagram fragment? Are the more
fragments? How can you tell?

13. What fields change in the IP header between the first and second fragment?

Now find the first ICMP Echo Request message that was sent by your computer after you
changed the Packet Size in pingplotter to be 3500.

14. How many fragments were created from the original datagram?
15. What fields change in the IP header among the fragments?

**WiresharkExercises.pdf**

This file is too large to display. [View in new window](https://www.sweetstudy.com/files/wiresharkexercises-pdf)

**Wireshark_HTTP_Sept_15_2009.pdf**

This file is too large to display. [View in new window](https://www.sweetstudy.com/files/wireshark-http-sept-15-2009-pdf)

**WiresharkQuickStartGuide.pdf**

This file is too large to display. [View in new window](https://www.sweetstudy.com/files/wiresharkquickstartguide-pdf)

**## Assignment2_Winter_2025_MSIT_650_Networking_Project2.pdf**

Nova Southeastern University

College of Engineering and Computing

Winter 2025 – Master Level Course

Term Code: 202530 – CRN: 30675 Sec: L01 Cr: 3.0

Dates: 8 weeks: 01/06/2025 – 03/02/2025

MSIT 650 Platform and Network Tech (3 Credits)

Assignment 2

Please refer to the course calendar and syllabus for assignment due date

and assignment grade percentage.

Your documents must be submitted before the due date on the proper

blackboard assignment number (assignment 2)

Your document for this project will be submitted to BlackBoard

(Assignment 2) in one of the following file formats: ASCII, MS Word,

PDF, or Compressed (ZIP).

Assignment 2:

This assignment will involve you using a tool called Wireshark, it works

on almost all operating systems. This is a powerful tool that can be used

to explore networking.

The link is:

http://www.wireshark.org/download.html

The assignment provides a quick start guide to help you get started and

involves completing 5 basic exercises and then 3 specific exercises which

include HTTP, IP and SSL, for a total of eight exercises.

1) Wireshark Exercises (this includes 5 exercises to help get started)

2) WiresharK_HTTP

3) Wireshark_IP

4) Wireshark_SSL

The exercises are self-explanatory, and you only need to carefully follow

the steps provided by each exercise.

If you even remotely do not understand the assignment, please email me

and I will try to clarify further.

Note:

The exercises are based around a book: Computer Networking: A Top

down Approach, 5th edition by J.F. Kurose, K.W Ross.

This book is not necessary but might be helpful although may provide far

more detail than necessary to complete the assignment.

[http://www.wireshark.org/download.html](http://www.wireshark.org/download.html)

Between YouTube and the Internet there are numerous examples on

Wireshark, use these as guides.

Regards

Dr. Kane

**## Wireshark_SSL_Sept_15_2009.pdf**

Wireshark Lab: SSL

Version: 2.0
© 2009 J.F. Kurose, K.W. Ross. All Rights Reserved

Computer Networking: A Top-
down Approach, 5th edition.

In this lab, we’ll investigate the Secure Sockets Layer (SSL) protocol, focusing on the
SSL records sent over a TCP connection. We’ll do so by analyzing a trace of the SSL
records sent between your host and an e-commerce server. We’ll investigate the various
SSL record types as well as the fields in the SSL messages.

1. Capturing packets in an SSL session

The first step is to capture the packets in an SSL session. To do this, you should go to
your favorite e-commerce site and begin the process of purchasing an item (but
terminating before making the actual purpose!). After capturing the packets with
Wireshark, you should set the filter so that it displays only the Ethernet frames that
contain SSL records sent from and received by your host. (An SSL record is the same
thing as an SSL message.) You should obtain something like screenshot on the previous
page.

If you have difficulty creating a trace, you should download the zip file
http://gaia.cs.umass.edu/wireshark-labs/wireshark-traces.zip and extract the ssl-ethereal-
trace-1 packet trace.

2. A look at the captured trace

Your Wireshark GUI should be displaying only the Ethernet frames that have SSL
records. It is important to keep in mind that an Ethernet frame may contain one or more
SSL records. (This is very different from HTTP, for which each frame contains either one
complete HTTP message or a portion of a HTTP message.) Also, an SSL record may not
completely fit into an Ethernet frame, in which case multiple frames will be needed to
carry the record.

1. For each of the first 8 Ethernet frames, specify the source of the frame (client or
server), determine the number of SSL records that are included in the frame, and
list the SSL record types that are included in the frame. Draw a timing diagram
between client and server, with one arrow for each SSL record.

2. Each of the SSL records begins with the same three fields (with possibly different
values). One of these fields is “content type” and has length of one byte. List all
three fields and their lengths.

ClientHello Record:

3. Expand the ClientHello record. (If your trace contains multiple ClientHello
records, expand the frame that contains the first one.) What is the value of the
content type?

4. Does the ClientHello record contain a nonce (also known as a “challenge”)? If so,
what is the value of the challenge in hexadecimal notation?

5. Does the ClientHello record advertise the cyber suites it supports? If so, in the
first listed suite, what are the public-key algorithm, the symmetric-key algorithm,
and the hash algorithm?

ServerHello Record:

6. Locate the ServerHello SSL record. Does this record specify a chosen cipher
suite? What are the algorithms in the chosen cipher suite?

7. Does this record include a nonce? If so, how long is it? What is the purpose of the
client and server nonces in SSL?

8. Does this record include a session ID? What is the purpose of the session ID?
9. Does this record contain a certificate, or is the certificate included in a separate

record. Does the certificate fit into a single Ethernet frame?

Client Key Exchange Record:

10. Locate the client key exchange record. Does this record contain a pre-master
secret? What is this secret used for? Is the secret encrypted? If so, how? How long
is the encrypted secret?

Change Cipher Spec Record (sent by client) and Encrypted Handshake Record:

11. What is the purpose of the Change Cipher Spec record? How many bytes is the
record in your trace?

12. In the encrypted handshake record, what is being encrypted? How?
13. Does the server also send a change cipher record and an encrypted handshake

record to the client? How are those records different from those sent by the client?

Application Data

14. How is the application data being encrypted? Do the records containing
application data include a MAC? Does Wireshark distinguish between the
encrypted application data and the MAC?

15. Comment on and explain anything else that you found interesting in the trace.

**## Wireshark_IP_Sept_15_2009.pdf**

Wireshark Lab: IP

Version: 2.0
© 2009 J.F. Kurose, K.W. Ross. All Rights Reserved

Computer Networking: A Top-
down Approach, 5th edition.

In this lab, we’ll investigate the IP protocol, focusing on the IP datagram. We’ll do so by
analyzing a trace of IP datagrams sent and received by an execution of the traceroute
program (the traceroute program itself is explored in more detail in the Wireshark
ICMP lab). We’ll investigate the various fields in the IP datagram, and study IP
fragmentation in detail.

Before beginning this lab, you’ll probably want to review sections 1.4.3 in the text and
section 3.4 of RFC 2151 [ftp://ftp.rfc-editor.org/in-notes/rfc2151.txt] to update yourself
on the operation of the traceroute program. You’ll also want to read Section 4.4 in
the text, and probably also have RFC 791 [ftp://ftp.rfc-editor.org/in-notes/rfc791.txt] on
hand as well, for a discussion of the IP protocol.1

1. Capturing packets from an execution of traceroute

In order to generate a trace of IP datagrams for this lab, we’ll use the traceroute
program to send datagrams of different sizes towards some destination, X. Recall that
traceroute operates by first sending one or more datagrams with the time-to-live
(TTL) field in the IP header set to 1; it then sends a series of one or more datagrams
towards the same destination with a TTL value of 2; it then sends a series of datagrams
towards the same destination with a TTL value of 3; and so on. Recall that a router must
decrement the TTL in each received datagram by 1 (actually, RFC 791 says that the
router must decrement the TTL by at least one). If the TTL reaches 0, the router returns
an ICMP message (type 11 – TTL-exceeded) to the sending host. As a result of this
behavior, a datagram with a TTL of 1 (sent by the host executing traceroute) will
cause the router one hop away from the sender to send an ICMP TTL-exceeded message
back to the sender; the datagram sent with a TTL of 2 will cause the router two hops
away to send an ICMP message back to the sender; the datagram sent with a TTL of 3

1 All references to the text in this lab are to Computer Networking: A Top-down Approach, 5th edition.

will cause the router three hops away to send an ICMP message back to the sender; and
so on. In this manner, the host executing traceroute can learn the identities of the
routers between itself and destination X by looking at the source IP addresses in the
datagrams containing the ICMP TTL-exceeded messages.

We’ll want to run traceroute and have it send datagrams of various lengths.

 Windows. The tracert program (used for our ICMP Wireshark lab) provided
with Windows does not allow one to change the size of the ICMP echo request
(ping) message sent by the tracert program. A nicer Windows traceroute
program is pingplotter, available both in free version and shareware versions at
http://www.pingplotter.com. Download and install pingplotter, and test it out by
performing a few traceroutes to your favorite sites. The size of the ICMP echo
request message can be explicitly set in pingplotter by selecting the menu item
Edit-> Options->Packet Options and then filling in the Packet Size field. The
default packet size is 56 bytes. Once pingplotter has sent a series of packets with
the increasing TTL values, it restarts the sending process again with a TTL of 1,
after waiting Trace Interval amount of time. The value of Trace Interval and the
number of intervals can be explicitly set in pingplotter.

 Linux/Unix. With the Unix traceroute command, the size of the UDP
datagram sent towards the destination can be explicitly set by indicating the
number of bytes in the datagram; this value is entered in the traceroute
command line immediately after the name or address of the destination. For
example, to send traceroute datagrams of 2000 bytes towards
gaia.cs.umass.edu, the command would be:

%traceroute gaia.cs.umass.edu 2000

Do the following:

 Start up Wireshark and begin packet capture (Capture->Start) and then press OK
on the Wireshark Packet Capture Options screen (we’ll not need to select any
options here).

 If you are using a Windows platform, start up pingplotter and enter the name of a
target destination in the “Address to Trace Window.” Enter 3 in the “# of times to
Trace” field, so you don’t gather too much data. Select the menu item Edit-
>Advanced Options->Packet Options and enter a value of 56 in the Packet Size
field and then press OK. Then press the Trace button. You should see a
pingplotter window that looks something like this:

Next, send a set of datagrams with a longer length, by selecting Edit->Advanced
Options->Packet Options and enter a value of 2000 in the Packet Size field and
then press OK. Then press the Resume button.

Finally, send a set of datagrams with a longer length, by selecting Edit-
>Advanced Options->Packet Options and enter a value of 3500 in the Packet Size
field and then press OK. Then press the Resume button.

Stop Wireshark tracing.

 If you are using a Unix platform, enter three traceroute commands, one with

a length of 56 bytes, one with a length of 2000 bytes, and one with a length of
3500 bytes.

Stop Wireshark tracing.

If you are unable to run Wireshark on a live network connection, you can download a
packet trace file that was captured while following the steps above on one of the author’s
Windows computers2. You may well find it valuable to download this trace even if
you’ve captured your own trace and use it, as well as your own trace, when you explore
the questions below.

2 Download the zip file http://gaia.cs.umass.edu/wireshark-labs/wireshark-traces.zip and extract the file ip-
ethereal-trace-1. The traces in this zip file were collected by Wireshark running on one of the author’s
computers, while performing the steps indicated in the Wireshark lab. Once you have downloaded the
trace, you can load it into Wireshark and view the trace using the File pull down menu, choosing Open, and
then selecting the ip-ethereal-trace-1 trace file.

2. A look at the captured trace

In your trace, you should be able to see the series of ICMP Echo Request (in the case of
Windows machine) or the UDP segment (in the case of Unix) sent by your computer and
the ICMP TTL-exceeded messages returned to your computer by the intermediate
routers. In the questions below, we’ll assume you are using a Windows machine; the
corresponding questions for the case of a Unix machine should be clear. Whenever
possible, when answering a question you should hand in a printout of the packet(s) within
the trace that you used to answer the question asked. Annotate the printout to explain
your answer. To print a packet, use File->Print, choose Selected packet only, choose
Packet summary line, and select the minimum amount of packet detail that you need to
answer the question.

1. Select the first ICMP Echo Request message sent by your computer, and expand
the Internet Protocol part of the packet in the packet details window.

What is the IP address of your computer?

2. Within the IP packet header, what is the value in the upper layer protocol field?
3. How many bytes are in the IP header? How many bytes are in the payload of the

IP datagram? Explain how you determined the number of payload bytes.
4. Has this IP datagram been fragmented? Explain how you determined whether or

not the datagram has been fragmented.

Next, sort the traced packets according to IP source address by clicking on the Source
column header; a small downward pointing arrow should appear next to the word Source.
If the arrow points up, click on the Source column header again. Select the first ICMP
Echo Request message sent by your computer, and expand the Internet Protocol portion
in the “details of selected packet header” window. In the “listing of captured packets”
window, you should see all of the subsequent ICMP messages (perhaps with additional
interspersed packets sent my other protocols running on your computer) below this first
ICMP. Use the down arrow to move through the ICMP messages sent by your computer.

5. Which fields in the IP datagram always change from one datagram to the next
within this series of ICMP messages sent by your computer?

6. Which fields stay constant? Which of the fields must stay constant? Which fields
must change? Why?

7. Describe the pattern you see in the values in the Identification field of the IP
datagram

Next (with the packets still sorted by source address) find the series of ICMP TTL-
exceeded replies sent to your computer by the nearest (first hop) router.

8. What is the value in the Identification field and the TTL field?
9. Do these values remain unchanged for all of the ICMP TTL-exceeded replies sent

to your computer by the nearest (first hop) router? Why?

Fragmentation

Sort the packet listing according to time again by clicking on the Time column.

10. Find the first ICMP Echo Request message that was sent by your computer after
you changed the Packet Size in pingplotter to be 2000. Has that message been
fragmented across more than one IP datagram? [Note: if you find your packet has
not been fragmented, you should download the zip file
http://gaia.cs.umass.edu/wireshark-labs/wireshark-traces.zip and extract the ip-
ethereal-trace-1packet trace. If your computer has an Ethernet interface, a packet
size of 2000 should cause fragmentation.3]

11. Print out the first fragment of the fragmented IP datagram. What information in
the IP header indicates that the datagram been fragmented? What information in
the IP header indicates whether this is the first fragment versus a latter fragment?
How long is this IP datagram?

3 The packets in the ip-ethereal-trace-1 trace file in http://gaia.cs.umass.edu/wireshark-labs/wireshark-
traces.zip are all less that 1500 bytes. This is because the computer on which the trace was gathered has an
Ethernet card that limits the length of the maximum IP packet to 1500 bytes (40 bytes of TCP/IP header
data and 1460 bytes of upper-layer protocol payload). This 1500 byte value is the standard maximum
length allowed by Ethernet. If your trace indicates a datagram longer 1500 bytes, and your computer is
using an Ethernet connection, then Wireshark is reporting the wrong IP datagram length; it will likely also
show only one large IP datagram rather than multiple smaller datagrams.. This inconsistency in reported
lengths is due to the interaction between the Ethernet driver and the Wireshark software. We recommend
that if you have this inconsistency, that you perform this lab using the ip-ethereal-trace-1 trace file.

12. Print out the second fragment of the fragmented IP datagram. What information in
the IP header indicates that this is not the first datagram fragment? Are the more
fragments? How can you tell?

13. What fields change in the IP header between the first and second fragment?

Now find the first ICMP Echo Request message that was sent by your computer after you
changed the Packet Size in pingplotter to be 3500.

14. How many fragments were created from the original datagram?
15. What fields change in the IP header among the fragments?

**WiresharkExercises.pdf**

This file is too large to display. [View in new window](https://www.sweetstudy.com/files/wiresharkexercises-pdf)

**Wireshark_HTTP_Sept_15_2009.pdf**

This file is too large to display. [View in new window](https://www.sweetstudy.com/files/wireshark-http-sept-15-2009-pdf)

**WiresharkQuickStartGuide.pdf**

This file is too large to display. [View in new window](https://www.sweetstudy.com/files/wiresharkquickstartguide-pdf)