Homework #3

(Latest revision 01/30/2000)

01/30/2000: Changes in wording for the next time the class is offered.
01/17/2000: Updated reference to the lab about the nslookup command.

THIRD HOMEWORK ASSIGNMENT FOR CS 3000

Homework Assignment #3

1. Run the following traceroute commands and turn in a copy of the output they produce. (This problem is akin to #21.4 in Comer/Droms)

traceroute calstate.edu
traceroute ucsd.edu
traceroute whitehouse.gov
traceroute cs.harvard.edu
traceroute u-aizu.ac.jp

2. Run the command

ps -ef

on altair. Get the output and turn it in, along with in-line annotations that mark each server process and briefly explain what it does. Include a tally at the bottom that tells the total number of servers running on altair at the time you did the ps command. (Prepare for this by first looking up the definition of "server" in at least a couple of places. Also, you can ask me about this.)

3. Do problems 24.3 and 25.1 in Comer/Droms. For 25.1, be sure to contact servers on several different hosts. Don't contact only Sun Ultra's. Try some other hosts such as koko, yokuts, or ollie. Turn in a script showing the computer interaction you had when doing problem 25.1.

4. Do 26.9 in Comer/Droms. If you like use the directions for the lab on nslookup in the web space to help figure out what to do with nslookup. Set the querytype to PTR when you look up:

1.2.10.128.in-addr.arpa.

(Don't leave out the final period above.) Set the querytype to A when you look up:

arthur.cs.purdue.edu.

(Again, do not leave out the final period when you do the look up.) With your answer, include a script showing your session with nslookup. For full credit, you must succeed with both of the queries, and you must give an enlightening explanation of the results. You can ask me for help if you have difficulty.

5. Telnet to ishi, port 25. The command is:

telnet ishi.csustan.edu 25

What program answers? Enter:

EXPN cs3000

What happens? Next try:

EXPN john

and:

EXPN cs4000

What is the meaning of the output? End the telnet session by typing:

QUIT

Include a script of the session.

6. Do a version of problem 28.8 in Comer/Droms:

Prepare for this by first ftp'ing into www.cs.csustan.edu with the ftp command:

ftp www.cs.csustan.edu

When prompted for your "Name" enter ftp (not your login name). When prompted for "Password," enter your full e-mail address. Once you are logged in enter the command dir and you will be shown the listing of the root ftp directory. Save the names you see somewhere. Then disconnect by typing bye. Next, telnet to port 21 on www.cs.csustan.edu. Once connected type help. Then use the user and pass commands to get logged in as user ftp with your e-mail address as the password. (Use a little ingenuity, experiment, and I think you will discover how to do this. If you want to you can ask me or someone else for help.) Include a script showing your interaction with the FTP daemon. For full credit you must:

get logged in
succeed in changing directories to some subdirectory of ftp's root directory
succeed in getting ftp to tell you what directory you are in
give enlightening answers to the questions in the statement of problem 28.8 in Comer/Droms.

7. Do problem 29.5 in Comer/Droms. Include a copy of the document.