On Fri, Jan 28, 2011 at 10:52:42AM +0800, bangla desh wrote: ... > I am wondering, is there a dns rule/standard (or RFC) that explains about > delegation?
Here are some simple rules for DNS delegation. [If I have oversimplified, the generous souls on this mailing list will let me know!] (1) All publicly available authoritative name servers for a zone on the same internet MUST serve identical copies of the domain. [Split DNS is excepted, I think, by the modifiers.] (2) Not all authoritative name servers must be listed in NS records in the zone, but enough should be that the zone is available whenever any members of the zone are available. [This is not a technical requirement, it is merely prudent.] (3) The list of name servers (NS records) in the delegating (parent) zone MUST be identical to the list of name servers in the zone itself. (4) The delegating (parent) zone MUST have "glue" A records for any name server names that are in that zone itself or any "descendant" zones, but MUST NOT for any non-descendant name server names. For example: zone "example.int" is delegating "bd.example.int". The name servers are "ns.example.int", "ns.bd.example.int", "ns.support.in.example.int", and "ns.example.seato.int". The first one would have an A record in the delegating zone anyway. The second two MUST have "glue" A records because they both are in "descendant" zones. The last MUST NOT have a glue "A" record because it is NOT a descendant. (5) Any changes in the name servers of the delegated zone MUST be communicated freely between delegator and delegatee before the change, with a mutually agreed-on time to make the change (and using decreased TTLs etc. as usual with such a change). -- /*********************************************************************\ ** ** Joe Yao j...@tux.org - Joseph S. D. Yao ** \*********************************************************************/ _______________________________________________ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
