Placement of MX records

[phn at icke-reklam.ipsec.nu]

Al Licause <al.licause at compaq.com> wrote:

> I have noticed that if a A record immediately preceeds an MX record in
> our v8.2.2-P5 bind servers, that MX record will be associated with the

First : replace this bind, it has known security risks and
might compromize your security.


> A record and not the domain....for example:

> node1        IN        A                10.10.8.34
>                   IN        MX   10     mailhub.mydomain.com.

This is the way it's supposed to work.

The first record "node1 .." is interpreted at loading time as "node1.<domain>.<tld>

The second line in your example lacks LHS, then the closes preceeding LHS is used.


> #nslookup
>> set type=mx
>> mydomain.com

> We don't see the MX record.   The only way to see this MX record is to
> specify node1.mydomain.com to nslookup.     But if I either move the MX
> record above all A records or preface the MX record with either an "@"
> sign or the
> domainname as such:

> mydomain.com.        IN    MX        10  mailhub.mydomain.com.

> ....we then see the MX record in the nslookup query for the domain and
> not
> the node.

> Now, it is my understanding of sendmail and all other related programs
> that
> the outgoing connection is first sent to resolve the MX record for the
> remote
> domain.   The only way I can see this working to be able to resolve the
> MX
> records on the domain and not on a node.

> Have I misunderstood the intent of bind v8 in this case or is the
> database
> parsing in error ?

Yes, you have misunderstood. However the fix is quite easy, reorder the two lines.


And , do upgrade your bind !!


> Any help greatly appreciated.
> Al Licause




-- 
Peter Håkanson         
        IPSec  Sverige      (At the Riverside of Gothenburg, home of Volvo)
           Sorry about my e-mail address, but i'm trying to keep spam out.
	   Remove "icke-reklam" and it works.