Note: For each problem below, you need to give thorough justifications . 1.(4 po

Question

Note: For each problem below, you need to give thorough justifications.

1.(4 points) Problem 6, page 173. (The goal of this question is to get you to retrieve and read an RFC.)

2.(8 points) Problem 7, page 173.

3.(8 points) Problem 8, page 173. Note: besides questions a, b, and c given by the book, add one more question d as “Persistent HTTP without pipelining?”

Notice that question c implies “Persistent HTTP with pipelining”.

4.(8 points) The useful tool available on UNIX and Linux hosts is often used by the DNS administrators to explore the hierarchy of DNS servers and troubleshoot DNS problems. For this problem, you may either use your own computer running UNIX/Linux/Mac OS if you have one, or use the server.

First, man the dig command, and then run it to answer the following questions: what is the IP address of gaia.cs.umass.edu? Show the list of names of DNS servers that are involved in answering your query.

Justify your answers by redirecting the output(s) of your command(s) to a text file (please name it dig_output.txt) and attaching it to your submission.

Explanation / Answer

3.

Persistent HTTP :-
The HTTP request header contains
"Connection: Keep-Alive"
Means that once the connection is set up, it is not closed immediately after the task. Thus, it reduces server overhead of establishinng/ending connections. Also latency is reduced as the connection setup time is saved.

Persistent HTTP without pipelining :-
The client issues new request only when previous request gets complete, i.e, response has been received for the previous request.
Only one object is effective in a RTT. To deal with this, parallelism can be implemented at server, so that # of object = # of connections can be served at a time.

4.

What is the IP address of gaia.cs.umass.edu?
dig gaia.cs.umass.edu > dig_output.txt

Show the list of names of DNS servers that are involved in answering your query.

dig gaia.cs.umass.edu ns > dig_output.txt
OR
dig -x IP-address_obtained_from_above_command > dig_output.txt

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.