DNS Exercise 1
--------------

===========
Preparation
===========

1. Log in using SSH/Putty/... to your Auth1 machine:

  (i.e. for group 1, you would use 10.0.X,1)

    $ ssh @10.0.X.1

    *** PLEASE MAKE SURE YOU ARE LOGGED IN TO YOUR 'Auth1' MACHINE ***
              
				  
2. On your Auth1 machine, modify /etc/resolv.conf temporarily
   to point 1.1.1.1 for this exercise 
   
    $ sudo ee /etc/resolv.conf
or
    $ sudo vi /etc/resolv.conf

---- Before
search dns.nsrc.org
nameserver 8.8.8.8

---- After
search dns.nsrc.org
#nameserver 8.8.8.8
nameserver 1.1.1.1

===
DIG
===

1. Issue DNS queries using 'dig':

1a. Run each command, look for the ANSWER section and write down the result.
    Make a note the TTL as well.

Repeat the command. Is the TTL the same? Are the responses Authoritative?

                                        RESULT 1            RESULT 2
                                        --------            --------
    $ dig your-favorite-domain a
    $ dig www.google.com. a
    $ dig afnog.org. mx
    $ dig NonExistentDomain.sometld any
    $ dig tiscali.co.uk. txt
    $ dig www.afrinic.net aaaa
    $ dig ipv6.google.com aaaa

1b. Now send some queries to another caching server.

    (Run each of the following twice, and note the time in ms for each attempt)

    $ dig @9.9.9.9 news.bbc.co.uk. a
    $ dig @resolver1.opendns.com yahoo.com. a
    $ dig @<a server of your choice> <domain of your choice> a

    How long did it take each answer to be received? (on the first, and
    on the second lookup)

========
Clean-up
========

1. Revert the modification of /etc/resolv.conf
   
    $ sudo ee /etc/resolv.conf
or
    $ sudo vi /etc/resolv.conf

---- Before
search dns.nsrc.org
#nameserver 8.8.8.8
nameserver 1.1.1.1

---- After
search dns.nsrc.org
nameserver 8.8.8.8
#nameserver 1.1.1.1