In class exercises, September 23, 2014.

Groups:	zeus.vse.gmu.edu, 
	root server(s)
	com server (s)
	somewhere.com server(s)
	someplace.somewhere.com

Background:

pammann@Zeus:~$ cat /etc/resolv.conf
search vse.gmu.edu vsnet.gmu.edu
nameserver 129.174.68.227
nameserver 129.174.97.3
nameserver 129.174.1.3

Run "dig +trace someplace.somewhere.com" on a zeus.vse.gmu.edu server to see
details of name resolution.

A sample root zone file is available here:

ftp://rs.internic.net/domain/root.zone


Exercise:

We are running a TCP/IP socket program on zeus.vse.gmu.edu
and the program tries to open a socket on 

    someplace.somewhere.com

How is this connection made?  That is, how is this request turned into an IP address?

0) What is the "search" line for?

1) Who does zeus.vse.gmu.edu ask?

2) Might this server already know the answer?  How?

3) If the server doesn't know, what does it do?

4) What protocol is used to send this request: TCP or UDP?  Why?

5) What is the complete sequence?

6) What gets cached, and where?   (What is an "A" or "AAAA" record?)

7) How long do cached values last?

8) What is a security problem with caching?

9) What could be recursive?  What could be iterative?