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Exercise #2.2
Download, compile and install dnstracer (instructions will be provided).
Use dnstracer to look at:
Using the server ns1.airmail.net, lookup www.airmail.net (use nslookup, dig or host). Can you do a whole zone transfer? (e.g. host -l airmail.net ns1.airmail.net)
Notes:
If you get a “* * *” answer, it could be that the DNS server being queried is down. For whatever reason, it is not responding to the request.
If you see a “lame” server, then that host claims to have authoritative information for a particular zone, but in reality it does not.
Finally, you might see an address like, 2001:0c50:ffff:0001:02e0:18ff:fe95:b22f, which indicates that the name server being queried has an IPv6 address or it may indicate a valid IPv6 answer for the host being queried for. The program might not be able to handle IPv6 DNS queries at this time. Use the -4 (which means just IPv4) option to dnstracer to prevent IPv6 queries.