Register.com DNS hosting issues

Randy Bush randy at psg.com
Sat Apr 4 17:41:12 CDT 2009


> IMHO, fate-sharing as a strategy for increasing availability is
> somewhat underrated.

from rfc 2182 

3.3. A Myth Exploded

   An argument is occasionally made that there is no need for the domain
   name servers for a domain to be accessible if the hosts in the domain
   are unreachable.  This argument is fallacious.

     + Clients react differently to inability to resolve than inability
       to connect, and reactions to the former are not always as
       desirable.
     + If the zone is resolvable yet the particular name is not, then a
       client can discard the transaction rather than retrying and
       creating undesirable load on the network.
     + While positive DNS results are usually cached, the lack of a
       result is not cached.  Thus, unnecessary inability to resolve
       creates an undesirable load on the net.
     + All names in the zone may not resolve to addresses within the
       detached network.  This becomes more likely over time.  Thus a
       basic assumption of the myth often becomes untrue.

   It is important that there be nameservers able to be queried,
   available always, for all forward zones.

randy




More information about the NANOG mailing list