Could some MX expert help by checking this MX record syntax in a virtual host SOA file?

[Joseph S D Yao]

On Tue, Jul 18, 2000 at 06:42:26PM +1000, Robert Chalmers wrote:
> I'm checking the syntax of this example, but it doesn't seem right.
>   I set up a similar virtual domain on my system, to check it out. The
> original I found is first, followed by my set up to test the theory. I
> thought I had a grip of all this - but it seems to get more confusing as I
> get older :-)
> 
> This is the original, and apparently works fine.  But I thought you couldn't
> put "other" domains into an soa record, as is happening  here with the
> 'mail' entry ....  which resolves to mail.waldorfcanberra.com.au - when in
> actual fact it isn't.

You can certainly put any domains you want into an SOA record.  They
just need to be correct!  If ns.inature.com.au is the name server, then
you should put it there.

The output from the "ls" command to 'nslookup' looks like it has
unterminated output on the right, but it is a fully qualified domain
name.

> > ls -t any waldorfcanberra.com.au
> [ns.inature.com.au]
>  waldorfcanberra.com.au.        SOA   ns.inature.com.au
> hostmaster.inature.com.au. (2000060910 10800 3600 3600000 86400)
>  waldorfcanberra.com.au.        NS    ns.inature.com.au
>  waldorfcanberra.com.au.        NS    ns1.telstra.net
>  waldorfcanberra.com.au.        MX    10   mail.waldorfcanberra.com.au
>  waldorfcanberra.com.au.        MX    50   postoffice.telstra.net
>  waldorfcanberra.com.au.        A     203.59.126.78
>  mail                                      A     203.38.96.33
>  www                                     A     203.59.126.78
>  waldorfcanberra.com.au.        SOA   ns.inature.com.au
> hostmaster.inature.com.au. (2000060910 10800 3600 3600000 86400)
> >
> ................

> The setup I used on my server to duplicate this, looks like this, naturally
> the NS are different etc, and the mail server is my own server, however -
> the nslookup is about the same ... So, is it kosher to use syntax like that
> mail........A xxx.xxx.xxx entry.??

Sure. Dot-terminated.  ;-)

...
> mail.waldorfcanberra.com.au actually resolves to 203.1.96.5 - which is my
> main (true, not virtual) server, also the mail server. So then 203.1.96.5
> will try and handle the mail, and failing that, pass it off to
> postoffcie.telstra.net ... I presume??

No.

A remote mail server will try first one mail server.  If that mail
server is not accepting connections, then it will try the second one.
But if it starts to make a connection, it will never try the second
one, even if the first one fails.  And the first one will not pass it
on to the second one if delivery fails, just because it's a
lower-precedence mail server in DNS!  Any arrangements like that have
to be programmed into 'sendmail', or whatever your MTA is.

-- 
Joe Yao				jsdy at cospo.osis.gov - Joseph S. D. Yao
COSPO/OSIS Computer Support					EMT-B
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