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Re: Detecting a non-existent domain

  • From: Kee Hinckley
  • Date: Wed Sep 24 15:15:16 2003 
At 10:24 AM -0400 9/24/03, John A. Martin wrote:

 >>>>> "Kee" == Kee Hinckley

 "RE: Detecting a non-existent domain"
  Tue, 23 Sep 2003 20:16:04 -0400

    Kee> At 3:15 PM -0700 9/23/03, David Schwartz wrote:
    >> How would you do this before? Does an A record for a hostname
    >> mean that a host with that name exists? If so, then all *.com
    >> 'hosts' now 'exist'. If not, what did you mean by exist before?

I just lurk nanog so my question probably doesn't count.  Anyway,
whats wrong with checking what used to be called "the DNS invariant",
ie. name <-> ip queries should agree as in
That seems like it would work as well. In my case I need to make use of the A and MX records for other things anyway, so I might as well go that path. I'd need to sit down and see which mechanism uses the least queries.

I'm concerned though that all these mechanisms could fall apart if Verisign decided to start using a third-party content provider to distribute the load on their server.
--
Kee Hinckley
http://www.messagefire.com/ Next Generation Spam Defense
http://commons.somewhere.com/buzz/ Writings on Technology and Society

I'm not sure which upsets me more: that people are so unwilling to accept
responsibility for their own actions, or that they are so eager to regulate
everyone else's.