dig strangeness

[Tom]

"Jim Reid" <jim at rfc1035.com> wrote in message
news:bhgi63$1vsi$1 at sf1.isc.org...
> >>>>> "Tom" == Tom  <bartling at io.com> writes:
>
>     Tom> When I try to find the name server for the problem
>     Tom> organization, it gives me two different responses depending
>     Tom> on how I ask. If I "dig mail.ajcds.org.", it gives the
>     Tom> correct info. If I "dig mail.ajcds.org. mx" it tells me that
>     Tom> the SOA identifying the name server as "marge.springfield.com."
>
>     Tom> I get the same results, even when logged on to another server
>     Tom> or digging another name server ("dig
>     Tom> @ns1.sierratech.com. mail.ajcds.org. mx" still shows
>     Tom> marge.springfield.com. as the name server).
>
>     Tom> I don't understand why specifying the mx info when digging
>     Tom> would return different results. Any help would be greatly
>     Tom> appreciated.
>
> The name servers are returning the same answers whenever you lookup
> the MX records for this name. This is correct and to be expected.
> Consistency in the DNS is good. You're not getting different results
> even though you seem to think that's the case. You're confused because
> the (consistent) answers don't match what you thought you'd get.
>
> The dig output you provided showed EMPTY Answer Sections and a NOERROR
> response. That means there were no resource records of the requested
> type for the name that was looked up. In short, there are no MX
> records for mail.ajcds.org. This name does exist as other record types
> however. By default, dig asks for A records unless you explicitly
> state what type of resource record you want. So the first result from
> dig you provided shows there is/was an A record for mail.ajcds.org.
> The output from your second dig lookup shows there are no MX records
> for mail.ajcds.org. That appears to be the case even though it doesn't
> appear to be what you want/expect.
>
> A SOA record in the Authority Section of a DNS reply -- which is what
> was returned when you looked for the non-existent MX record -- is a
> standard way for a name server to say "the name and record type you're
> looking for does not exist".
>

Thanks, Jim. That helps me understand the results that I'm seeing. I have
another question. When I specify a server when doing a dig and it returns
the root servers, is that server only setup to answer for domain names that
it is the SOA? For example, "dig @dns1.rr.com. tombartling.com." returns
only the root servers.

Thanks,
Tom