some DNS servers return IP, some return list of root servers...why?

[Kevin Darcy]

Chris Weiss wrote:

> "Barry Margolin" <barmar at genuity.net> wrote in message
> news:QJq65.89$MK2.1998 at burlma1-snr2...
> > In article <9xo65.178$4h2.45605 at news.dbn.net>,
> > Chris Weiss <chrisweiss at wilsonmfg.com> wrote:
> > 151.164.1.1 (ns1.swbell.net) has recursion disabled; you can tell this
> > because the "flags" section of the response doesn't include "ra".  It's
> not
> > intended to be used by resolvers, it's just for answering queries about
> the
> > domains that swbell.net hosts.
> > If the people who can't send you mail have 151.164.1.1 in their resolver
> > configuration, they're misconfigured.
> >
> > --
> > Barry Margolin, barmar at genuity.net
> > Genuity, Burlington, MA
> > *** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to
> newsgroups.
> > Please DON'T copy followups to me -- I'll assume it wasn't posted to the
> group.
> >
>
> that interesting...because that was just one example.  There are many other
> people that have the same problem, but only to us.  Besides, it's the mail
> servers that can't resolve so if this were really the case then these people
> would not be able to send to anyone outside their comapany.  Any other
> guesses or am I way off on the way I see this?

The fact that 151.164.1.1 is only giving root-server referrals for
wilsonmfg.com is a red herring: that's what non-recursive servers are
*supposed* to do if they don't happen to have any specific information about
the name being queried.

I think the bigger problem is that the only NS which is being given out by the
authoritative servers for wilsonmfg.com is ns.wilsonmfg.com and the nameserver
on that box doesn't seem to be answering queries currently. Your NS list should
include *every* server which you intend to be used for answering iterative
queries about the zone. If you only have one NS in your NS list, you have no
redundancy.

Oh, and it doesn't work to use an IP address as an MX target, so wilsonmfg.com
doesn't have any MX redundancy either...


- Kevin