Is this scenario possible?

[Barry Margolin]

In article <mailman.1996.1389470377.20661.bind-users at lists.isc.org>,
 Blason R <blason16 at gmail.com> wrote:

> Hey all,
> 
> Pertaining to the same discussion. Can someone validate below zone files
> and named.conf files? What I wanted to achieve here is; I wanted to make
> mail.example.com as my sub domain and give them A record so that I could
> load balance the traffic on LBs since my LBs are offering inbuilt DNS server
> 
> example.com
> NS = ns1.example.com 1.1.1.1
> ns2.example.com 2.2.2.2
> 
> #############################################
> #
> # example.com MAIN ZONE FILE
> #
> #############################################
> zone "example.com" in{
>   type master;
>   file "master/master.example.com";
>   // explicitly allow slave zone transfer
>   allow-transfer {2.2.2.2;};
> };
> 
> 
> ##################################
> #
> # master.example.com
> ##################################
> $TTL 2d
> $ORIGIN example.com.
> @              IN      SOA   ns1.example.com. hostmaster.example.com. (
>                2003080800 ; serial number
>                2h         ; refresh =  2 hours
>                15M        ; update retry = 15 minutes
>                3W12h      ; expiry = 3 weeks + 12 hours
>                2h20M      ; minimum = 2 hours + 20 minutes
>                )
> 
>               IN      NS     ns1.example.com.
>               IN      NS     ns2.example.com.
> 
>               IN      MX     10 mx01.example.com.
> IN MX 20 mx02.example.com.
> 
> ns1           IN      A      1.1.1.1
> ns2           IN      A      2.2.2.2
> ; A record for mail server above
> mx01           IN      A      20.20.20.20
> mx02 IN A 30.30.30.30
> 
> #######################################################
> 
> $ORIGIN mail.example.com.
> 
> @             IN      NS     ns3.mail.example.com.
> 
> ; the next name server points to ns1 in the example.com zone above
>               IN      NS     ns1.example.com.
> ; sub-domain address records for name server only - glue record
> ns3           IN      A      20.20.20.21 ; 'glue' record
> 
> ******************************************************
> ******************************************************
> #############################################
> #
> # mail.example.com MAIN ZONE FILE
> #
> #############################################
> zone "mail.example.com" in{
> type master;
> file "master/master.mail.example.com";
> 
> };
> 
> #############################################
> # mail.example.com zone file
> #############################################
> #
> 
> $TTL 2d ; default TTL = 2 days
> $ORIGIN mail.example.com.
> @              IN     SOA   ns3.mail.example.com.
> hostmaster.mail.example.com. (
>                2003080800 ; serial number
>                2h         ; refresh =  2 hours
>                15M        ; update retry = 15 minutes
>                3W12h      ; expiry = 3 weeks + 12 hours
>                2h20M      ; minimum = 2 hours + 20 minutes
>                )
> ; sub-domain name servers
>                   IN      NS     ns3.mail.example.com.

You also need:

                    IN      NS     ns1.example.com.

> 
> ; A records for name servers above
> ns3               IN      A      20.20.20.21
> 
> ; A record for mail server above
> mail               IN      A      20.20.20.20
> mail IN A 30.30.30.30

These will create A records for mail.mail.example.com. Is that what you 
wanted? If you just want mail.example.com, it should be:

@  IN A 20.20.20.21
   IN A 30.30.30.30

-- 
Barry Margolin
Arlington, MA