[84990] in North American Network Operators' Group
Re: Weird DNS issues for domains
daemon@ATHENA.MIT.EDU (Mark Andrews)
Thu Sep 29 19:52:20 2005
Date: Fri, 30 Sep 2005 09:51:44 +1000 (EST)
From: Mark Andrews <Mark_Andrews@isc.org>
To: nanog@merit.edu, matthew@crocker.com
In-Reply-To: <A310E761-5459-440B-BA92-E160A45550AB@crocker.com>
Cc:
Errors-To: owner-nanog@merit.edu
In article <A310E761-5459-440B-BA92-E160A45550AB@crocker.com> you write:
>
>>
>> I just tested it from a Verizon DSL host and it worked.
>>
>> You might want to consider reading RFC 2182 though, particularly the
>> part about geographically diverse nameservers.
>
>Yeah, yeah, that is overrated. If my site goes dark and my DNS goes
>down it doesn't really matter as the bandwidth and the web server
>will also be down. Having a live DNS server in another part of the
>country won't help if the access routers handling the traffic for the
>T1 to the school is also down.
>
>Geographically diverse name servers sounds great in theory but for
>this application it won't gain any redundancy.
People say this but then they don't see the impact of not
having DNS servers available.
The DNS was designed with the idea that atleast one of the
nameservers for a zone would always be reachable. A zone
that is unreachable results in the caching servers using
up resouces at 1000 times the normal rate. Milli-seconds
to tens of seconds.
Mark
