command to locate nameservers question

[Ben Pfaff]

"Don Chorman" <chormand@pilot.msu.edu> writes:

> Can you tell me what "Non-authoritative answer:
> means" or "Authoritative answer:" means?

An authoritative answer is one coming directly from the DNS
server for a domain.  A non-authoritative answer comes from a DNS
server that has cached the information for the domain; it is not
considered authoritative because it is possible that the
information has changed in the meantime.

You will find that DNS servers cache the results of their
lookups.  For instance, my local nameserver on
pfaffben.user.msu.edu hadn't had a request for www.gnu.org for a
while, so its IP wasn't in the cache.  But the second time I
requested it, it remembered it and thus the information wasn't
considered authoritative the second time around:

    blp:~(0)$ nslookup www.gnu.org
    Server:  localhost
    Address:  127.0.0.1

    Name:    www.gnu.org
    Address:  198.186.203.18

    blp:~(0)$ nslookup www.gnu.org
    Server:  localhost
    Address:  127.0.0.1

    Non-authoritative answer:
    Name:    www.gnu.org
    Address:  198.186.203.18

    blp:~(0)$

You are probably not running a nameserver of your own.  I do
because I sometimes run a LAN on an internal network and like to
have name resolution work properly without maintaining /etc/hosts
everywhere.