dig strangeness

[Jim Reid]

>>>>> "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".