Unless the assignment says otherwise, all answers are limited to 50 words. Longer answers will not be graded. Assignments are due at the start of class. Please submit them using email to So that we don't all share infections, please don't use email attachments.

Assignment 1

1. Which is better, circuit switching or packet switching?  Why?

2. Read all of the site,  Under what circumstances are late homeworks accepted?  When is the date when you must have a project topic that has been accepted by the professor?

3. How does the value of a network vary as the number of participants increases?  Why?

4. What is the Internet?

5. Suppose the Internet has not been invented yet but everyone wants one, so you are in charge of the design. The first question that you are asked is about addressing. What will you need to have addresses for? Which of these addresses should be fixed in hardware and which can be changed by an administrator?

6.  Have you completed the mandatory prerequisite?  If not, why should you be permitted to take this course?

7. Install Wireshark on a computer that you will be using for class, and submit a screenshot of an Ethernet frame captured by Wireshark.

Assignment 2

1. How does an Ethernet switch differ from an Ethernet hub?

2. Why are network systems layered?

3. What happens if we increase the number of hosts in an Ethernet beyond 1024?  Why?

4. What is the difference in terms of network traffic between two Ethernet segments connected by a bridge and two segments connected by an adaptive bridge?  Why?

5. Layering is found in many processes that we deal with.  Describe the process layering that is present in air travel, from the time of booking to baggage pickup at your desitnation.  You may use 100 words to answer this question!

6. What is the Good Citizen Principle?

7. What is the most critical resource on the Internet?

Assignment 3

1. Comer 5.6

2. Comer 5.9

3. Comer 6.5

4. Comer 6.7

5. Comer 6.10

Assignment 4

1. Visit this link and sign up for a Webinar on the Internet of Things.  Plan to attend the Webinar.  Provide evidence that you have enrolled.

2.  Run Ping for, and and explain the results.  Note that if you get different results, you need to explain the differences.  You are to explain the reasons for the results that you obtained for each ping.

3. Run traceroute for the three sites in problem 2, and explain the results.

4. How does traceroute use ICMP commands?  Which commands does it use and just how does it use them? 

5. Comer 7.1

6. Comer 8.8

Assignment 5

1. What kinds of applications cannot run through a NAT box? 

2. Can a local address in a network behinid a NAT box be the same as a globally unique address?  Explain.

3. What are the IP addresses that are reserved for use by private networks?  What is the IP address for your own PC?  Is it one of these addresses?  Why or why not?   

4. Comer 10.5

5. Comer 10.11

6. Comer 11.4

7. Layering is found in many processes that we deal with. Describe the process layering that is present in air travel, from the time of booking to baggage pickup at your desitnation. Give a name to each layer.  You may use 100 words to answer this question!

Assignment 6

1. Comer 12.1

2. Comer 12.2

3. Comer 12.9

4. Comer 13.9

5. Comer 13.5

6.  If an IPv4 router finds that it needs to fragment a datagram that it is sending, and the "do not fragment" bit is set in the datagrams's header, what does it do?

Assignment 7

1. Carry out problem 3 of Assignment 4.  Explain the results by discussing how many hopes it took to reach various sites and why, and explain differences in elapsed time to reach the various sites.  When did the datagram leave the home ISP and enter an exchange point, or some other network that connects autonomous systems?  Which company's networks were used?  Why are the results as they are in each case?  Be sure to include,,, and in the hosts you test, in addition to the originally required host names. 

2.  Attend the Internet of Things webinar and summarize its important points in less than 100 words.

3. Does a multicasting router need to know how many subscribers are on a network that it connects to for a multicast group?  Explain.

4. Describe the efficiency gains of MPLS in terms of forwarding equivalence classes (FECs).  Hint:  check the RFC

5. Can there be more than one FEC for a single LSR?  Can there by more than one LSR for a single FEC?  Hint:  check the RFC

 Assignment 8

1. What are the two types of IGP, and how do they compare?  Which one of them appeals most to you, and why?

2. Comer 14.12

3. Comer 14.17

4. Comer 14.5

Assignment 9

1. Comer 23.3

2. Comer 23.5

3. Comer 23.13

4. Comer 23.15

5. Comer 23.1 

Assignment 10

Note:  for this assignment, you are encouraged to use the class email address to share information about port numbers and DNS addresses to use for problem 1. 

1. Use TELNET to send a test email message to  Save the dialogue and put it into your homework submission and explain it.

2. Use Wireshark to capture SMTP negotiation sessions, put screenshots of those sessions into your homework submission, and explain them.  Be sure the dialogue in the sessions is readable.  You don't have to include the entire Wireshark screen.

3. Use Wireshark to capture a DNS lookup as part of an SMTP activity.  Put this into your homework submission and explain it.

4. Go to the Web site and get a ticket for the Nov. 17 seminar at GWU on "Human Rights, Accountability, and Internet Governance:  A Panel Discussion", and show evidence that you have done so.  And attend!  ...there's free lunch...

 Assignment 11

1. Use html to compose a one-page summary of your project, including some sort of diagram.  This does not have to be long.  Include that in your submitted assignment, so that it displays properly in html email.  Use your full name, followed by HTML (in addition to the extension html) as the file name.  That is, if your name is John Smith, the file name would be johnsmithhtml.html

2. Use TELNET and HTTP to connect to and PUT your html page about your project to Show the HTML dialogue in your submission.

3. Use TELNET to make an FTP connection to, using the userid student and password scholar.  Upload your html project description.  For the filename, use your full name, as for problem 3, but add ftp to the name.  That is, if your name is John Smith, your file name for this problem would be johnsmithftp.html

4. Find and install a free FTP client with a GUI onto your computer.  Use the FTP client to upload your project description to, using the same credentials and file name as problem 3.

5. Compare the difficulty of problems 3 and 4.  Do you prefer the FTP client with a GUI or the use of TELNET?  Why?

6. Compare FTP and HTTP with regard to their use of out-of-band-communication.  Which of them uses it?  Why?

7. Suppose you were the IT manager for a small department at GWU.  You installed PCs on each desk and you have one router connected to the Internet.  You we not able to get IP addresses, so you are running NAT in your router.  You want to run Apache Traffic Server to cache Web pages for people in the Department.

Should you install Apache Traffic Server inside your local network, that is, downstream of your NAT box, or should you install it upstream, outside of your NAT box?  Why does it make a difference?