===================[ Configuring your IPv6 DNS lookup ]===================

The entry point for our IPv6 exercises is the subnet  test6.dartmouth.edu .
It has global IPv6 connectivity and presents several hosts such as
a.ns.test6.dartmouth.edu , the nameserver for names ending in .test6.dartmouth.edu,
and some others.

What is configured:        AAAA names and the NS record for test6.dartmouth.edu

What is _not_ configured:  any A records for these names.

So if you send queries to normal IPv4 servers for names such as test6.dartmouth.edu
("dig test6.dartmouth.edu" or "nslookup test6.dartmouth.edu"), these queries 
will fail. This is because these queries ask for A records, i.e., for IPv4 addresses 
associated with these names, and there aren't any. You need to ask for AAAA records,
i.e., IPv6 addresses, or for the NS (nameserver) records. 

The syntax for these is "dig aaaa <name>" and "nslookup -query=aaaa <name>"
for AAAA records, and similar for NS records.

Moreover, you will need to add an IPv6 DNS server to your system; your
default IPv4 nameservers most likely won't do the trick. This is because
most normal IPv4 nameservers do not have IPv6 connectivity, and when they 
try to ask for an authoritative nameserver for names in test6.dartmouth.edu 
(this is the meaning of the NS record), they will only get an IPv6
address, which they won't be able to contact. 

My suggestion is to use Google's public IPv6 DNS servers: 
    2001:4860:4860::8888  and  2001:4860:4860::8844

First, get some kind of IPv6 connectivity, e.g., via Hurricane Electric
Tunnelbroker or Miredo. Then test with ping6 that you can reach the above
Google addresses. Finally, use "dig @2001:4860:4860::8888 aaaa <name>"
to contact the specific server and not your default one.

If this works, you can add 2001:4860:4860::8888 or 2001:4860:4860::8844
to your /etc/resolv.conf  or /etc/network/interfaces to be used as defaults 
for name resolution (depending on how your system is configured; see
 https://www.howtoforge.com/debian-static-ip-address). For some systems,
only the first three "nameserver <address>" records in /etc/resolv.conf
matter (the rest are ignored), so make sure the IPv6 nameserver is within
the first three. 

If in doubt how DNS works, read the DNS primer in 
  http://unixwiz.net/techtips/iguide-kaminsky-dns-vuln.html

Note that the nameserver for test6.dartmouth.edu is D.J. Bernstein's TinyDNS
server. It will ignore incorrect queries or queries it does not understand;
so if you send such queries, they will time out.

Tasks: Find out the names of test6.dartmouth.edu authoritative nameserver 
        and of the host puzzle.test6.dartmouth.edu