North American Network Operators Group

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RE: VeriSign's rapid DNS updates in .com/.net

  • From: Sam Stickland
  • Date: Thu Jul 22 07:05:31 2004

Well, a naive calculation, based on reducing the TTL to 15 mins from 24
hours to match Verisign's new update times, would suggest that the number
of queries would increase by (24 * 60) / 15 = 96 times? (or twice that if 
you factor in for the Nyquist interval).

Any there any resources out there there that have information on global 
DNS statistics? ie. the average TTL currently in use.

But I guess it remains to be seen if this will have a knock on effect like 
that described below. Verisign are only doing this for the nameserver 
records at present time - it just depends on whether expection for such 
rapid changes gets pushed on down.

Sam

On Thu, 22 Jul 2004, Ray Plzak wrote:

> 
> Good point!  You can reduce TTLs to such a point that the servers will
> become preoccupied with doing something other than providing answers.
> 
> Ray
> 
> > -----Original Message-----
> > From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of
> > Daniel Karrenberg
> > Sent: Thursday, July 22, 2004 3:12 AM
> > To: Matt Larson
> > Cc: nanog@merit.edu
> > Subject: Re: VeriSign's rapid DNS updates in .com/.net
> > 
> > 
> > Matt, others,
> > 
> > I am a quite concerned about these zone update speed improvements
> > because they are likely to result in considerable pressure to reduce
> > TTLs **throughout the DNS** for little to no good reason.
> > 
> > It will not be long before the marketeers will discover that they do not
> > deliver what they (implicitly) promise to customers in case of **changes
> > and removals** rather than just additions to a zone.
> > 
> > Reducing TTLs across the board will be the obvious *soloution*.
> > 
> > Yet, the DNS architecture is built around effective caching!
> > 
> > Are we sure that the DNS as a whole will remain operational when
> > (not if) this happens in a significant way?
> > 
> > Can we still mitigate that trend by education of marketeers and users?
> > 
> > Daniel
>