THIRD HOMEWORK ASSIGNMENT FOR CS 3000

• for you to learn something by doing the problems, and
• for you to make answers that effectively show me what you know & understand.

• Run the command

  ps -ef

  on altair. (You don't have to log in at the console. You can use "ssh" to log in remotely from "anywhere.") Make a copy of the output. Find at least ten processes in the list that you are sure are servers. Under each line corresponding to one of your servers place a comment that marks the process as a server and states facts and evidence that prove it is a server. Turn in this edited output.
  
  ( Some help: Prepare for doing this problem by first reading the chapter in our text about client-server interaction. In the readout from the ps -ef command, look for processes owned by root whose names end in 'd'. Scan the first few lines of the man pages for these programs. To find out if a program is listening on a port, do the rpcinfo command and cat the /etc/inet/services file. You can do man services or man rpcinfo to get more information, or ask about these things in class. Using this information, you should be able to verify that many of the running processes are servers.)
  
  
• Do problems 30.1 and 30.2
  
  For 30.2, be sure to contact servers on several different hosts. Don't just contact servers on Sun Ultra's in the CS lab. Try some other hosts such as time-nw.nist.gov, www.boulder.nist.gov, tock.usno.navy.mil, and ptbtime1.ptb.de. Try using a search enging to find some public daytime servers (port 13). Try hosts in different timezones. Try at least four hosts. Turn in a script showing the computer interaction you had when doing problem 30.2.
  
  
• Do problems 35.5 and 35.6
  
  
• Do problem 36.3
  
  
• Do problem 37.5
  
  
• Do problem 40.4