Question on DNS Protocols

[John N Dvorak]

On 9 Jul 1999, The Cameleon wrote:

>Hi

>What will happen if I declare in my primary DNS some DNS different from
>what will be declared in the Internic base ?

There is no direct correlation between the SOA nameservers listed in DNS
and the authoritative nameservers you place in your zone file, though they
are often the same.  You can certainly list more NS entries in your zone
file than are listed in 'NIC.  You just need to make sure that those
nameservers can answer queries about the zone (or forward queries
appropriately, etc).

The authoritative nameservers associated with your 'NIC record (and
thus accessed by the root servers) are those nameservers which contain the
SOA information for the domain: they tell the world where they can look
for authoritative answers about a zone.  You could have 2 nameservers in
your 'NIC record, and any number of authoritative servers listed for
the zone.  Incidently, this is a critical part of the DNS process because
it allows the managers of the SOA for a zone the ability to delegate
authority for the zone to other nameservers without a need for modifying
a 'NIC domain record.

"Primary" is a depricated term.  We prefer to think of DNS in terms of
masters and slaves.  A master of a zone contains the master SOA record for
the zone.  Slaves poll zone information for a zone from the master of that
zone.  But slaves and masters are not important to the outside world.  For
example, the root servers do not care which servers are masters or slaves
(or what we consider primary and secondary).  It is very common to
specify slave servers for the purpose of answering non-recursive queries
for a zone, while you have your master zone information residing on an
unpublished master.

>
>
>
>Exemple:
>
>
>On the Sur l'Internic, I have :
>
>
>
>        Domaine1.com            Primary DNS:            212.208.1.1     
>ns1.domaine2.com
>                                Secondary DNS:  212.208.2.20    
>ns2.domaine2.com
>                                Secondary DNS:  212.208.3.30    
>ns3.domaine2.com
>
>On the 3 DNS above, I have only in NS :
>
>
>domaine1.com    IN      NS      ns1.iri.net.
>domaine1.com    IN      NS      ns2.iri.net.
>domaine1.com    IN      NS      ns3.iri.net.
>
>Thank you in advance for your replies.


===========================================
John N Dvorak | dvorak at capu.net
Director of Technology
CapuNet, LLC - Corporate Internet Solutions
(301) 881-4900 x8018
===========================================