what if central dns servers are blown up ?

[Alan Sparks]

skybuck wrote:
> 
> Howdy..
Yo.

> 
> I was just wondering what would happen if the dns servers were blown
> up which host the .com domains for example.
Lot of pissed-off people, including admins.  :-)

> 
> I think dns is a somewhat centralized technology ? Like all subdomains
> that end with .com have to be administrated centrally somewhere...
But they're not. Need to read up on it.  Thats's what all the slave
servers, geographically dispersed, are for.

> How does that work ? and if it is central... what would happen if they
> were blown up ?
DNS is a distributed database system.  Each zone (including the roots)
are replicated.  While there's a "master server," another server could
be "upgraded" to the master if necessary.

> Is there a fallback system or something like that ?
> Can it recover automatically or will it be manually... ?
Recovery would be automatic, resolvers and other name servers would just
start using servers they could contact.  If enough servers went down,
delays would be noticable. You'd have to blow up most of them to cause
widespread major problems.

> 
> Or would all sites ending with *.com like www.hotmail.com and
> www.google.com  no longer be reachable with dns ?
Nope, the world's porn supply would be still accessible.  :-)

> 
> Greetz
>   Skybuck.

-- 
Alan Sparks, Sr. UNIX Administrator     asparks at quris.com
Quris, Inc.                             (720) 836-2058