[113159] in North American Network Operators' Group
Re: Register.com DNS hosting issues
daemon@ATHENA.MIT.EDU (Randy Bush)
Sat Apr 4 18:43:21 2009
Date: Sun, 05 Apr 2009 07:41:12 +0900
From: Randy Bush <randy@psg.com>
To: Florian Weimer <fw@deneb.enyo.de>
In-Reply-To: <874ox4vyp0.fsf@mid.deneb.enyo.de>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
> 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
