Hang fire.. I dont see any reference to adjusting the TTL in the verisign announcement. They say they will update the zones every 5 minutes from the registry data. These are not the same things (or did I miss that bit?) Also, isnt a lot of this dependent on the NS records in the second level gtlds which is hosted by the ISPs.. so this part doesnt change? Steve On Thu, 22 Jul 2004, Sam Stickland wrote:
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