Matt Levine wrote:
When did this start?
Associating multiple IP addresses with a single name server (i.e., multiple A records with the same owner) in the com, net and org zones has always been possible with the NSI Registry/VeriSign Global Registry Services. This behavior is documented in the RRP protocol spec; please see RFC 2832, section 4.3.1.2. Whether or not a given registrar supports this is another matter and I don't know what each one allows. william@elan.net wrote:
Now it appears there is reverse situation - some registrars allow (and verisign no longer gives an error) to register dns servers in different domains all pointing to the same ip. I belive they may have some stupid idea to help/encourage using shared hosting and preserve ip space.
Err, no. The limitation of only one name server (i.e., A record) per IP address was an unfortunate Registry-based restriction that was removed on January 19 of this year. The motivation had nothing to do with "preserving ip space". There were several reasons for relaxing this restriction, not the least of which was that there wasn't a good reason for it in the first place. An immediate positive benefit is that it's no longer possible for someone to hold a given IP address hostage by registering a name server at that address. (Anyone can register a com/net/org name server at any IP address.) Matt -- Matt Larson <mlarson@verisign.com> VeriSign Global Registry Services