What is the sequence number of the TCP SYN segment that is used to initiate the TCP connection between the client computer and gaia.cs.umass.edu? What is it in the segment that identifies the segment as a SYN segment? 4. What is the sequence number of the SYNACK segment sent by gaia.cs.umass.edu to the client computer in reply to the SYN? What is the value of the Acknowledgement field in the SYNACK segment? What is it in the segment that identifies the segment as a SYNACK segment? 5. What is the sequence number of the TCP segment containing HTTP POST command? Hints: In order to find the POST command, you will need to dig into the packet content field at the bottom of the wireshark window
1. Start up your web browser and go to the http://gaia.cs.umass.edu/wireshark-labs/alice.txt and
retrieve an ASCII copy of Alice in Wonderland. Store this file somewhere on your computer
2. Next go to http://gaia.cs.umass.edu/wireshark-labs/TCP-wireshark-file1.html. You will
find a form to upload the text file.
3. Use the browse button in this form to enter the name of the file on your computer containing
Alice in Wonderland. Don’t yet press the “Upload alice.txt file” button in the form
4. Now start up Wireshark and begin packet capture.
5. Returning to your browser press the “Upload alice.txt file” button in the form to upload the
file to the gaia.cs.umass.edu server. Once the file has been uploaded, a short congratulations
message will be displayed in your browser window.
6. Stop the Wireshark packet capture
Answer the following questions:
1. What is the IP address and TCP port number used by client computer (source) that is
transferring the file to gaia.cs.umass.edu?
2. What is the IP address of gaia.cs.umass.edu? On what port number is it sending and receiving
TCP segments for this connection?
3. What is the sequence number of the TCP SYN segment that is used to initiate the TCP
connection between the client computer and gaia.cs.umass.edu? What is it in the segment that
identifies the segment as a SYN segment?
4. What is the sequence number of the SYNACK segment sent by gaia.cs.umass.edu to the
client computer in reply to the SYN? What is the value of the Acknowledgement field in the
SYNACK segment? What is it in the segment that identifies the segment as a SYNACK
segment?
5. What is the sequence number of the TCP segment containing HTTP POST command?
Hints: In order to find the POST command, you will need to dig into the packet content field
at the bottom of the wireshark window
6. What are the sequence numbers of the first six TCP segments? Consider the TCP segment
that contains HTTP POST as the first segment in the TCP connection.
7. When the acknowledgement for the first TCP segment received? What is the
acknowledgement number for that acknowledgement? Calculate the RTT value to get this
acknowledgement.
8. What is the length of each of the first six TCP segments?
Plot the following graph:
Select a TCP segment in the Wireshark’s “listing of captured-packets” window. Then select
the menu: Statistics-> TCP Stream Graph -> Time-Sequence-Graph(Stevens). Make a plot
that looks similar to the plot given in part 4 of the “Wireshark_TCP_v8.0.pdf” file uploaded
in the course content section of Blackboard
Question 9: In the graph each dot represents a TCP segment sent. What is meant by a set of
dots stacked above each other in the graph?
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 3 images
