nanog mailing list archives
FW: DNS TTL adherence
From: "Thurman, Steven" <steven.thurman () wamu net>
Date: Wed, 15 Mar 2006 09:34:21 -0800
On Wed, 15 Mar 2006, Simon Waters wrote:
This behavior is unfortunately not unique.Alas what others peoples servers do, shouldn't be an issue for you.
Your
problem is they can be coerced into a DoS attack, not that the data is
stale.
actually, dos-attack-aside, the interesting thing is that lots of
people
(original poster perhaps included) believe that TTL's are adhered to except in some marginal cases. I think Rodney's point is that they are
not
adhered to anywhere near as much as we would all like to believe :(
So, if you, or the original poster, is going to move
${important_resource}
around ip-wise keep in mind that your ${important_thing} may have to answer to more than 1 ip address for a period much longer than your
tuned
TTL :(
Thanks all for the responses. I do understand we may need to support the old IP addresses for sometime. I was hoping someone had performed a study out there to determine what a ratio maybe for us supporting an old IP address (I know our traffic profile will be unique for us thus it would only give us a general idea). For example if we change ip addresses will we need to plan on 20% traffic at old site on day1, 10% day2, 5%, day3, and so on...? There are also issues related to proxy servers and browser caching that are independent of DNS we will need to quantify to understand full risk. The more data we have will drive some of our decisions. Thanks again, Steve
Current thread:
- DNS TTL adherence Thurman, Steven (Mar 14)
- Re: DNS TTL adherence ennova2005-nanog (Mar 14)
- Re: DNS TTL adherence Joe Maimon (Mar 14)
- Re: DNS TTL adherence Simon Waters (Mar 15)
- Re: DNS TTL adherence Rodney Joffe (Mar 15)
- Re: DNS TTL adherence Simon Waters (Mar 15)
- Re: DNS TTL adherence Jon Lewis (Mar 15)
- Re: DNS TTL adherence Christopher L. Morrow (Mar 15)
- Re: DNS TTL adherence Joe Maimon (Mar 14)
- Re: DNS TTL adherence ennova2005-nanog (Mar 14)
- <Possible follow-ups>
- FW: DNS TTL adherence Thurman, Steven (Mar 15)
- RE: DNS TTL adherence Sharad Agarwal (Mar 15)
- Re: DNS TTL adherence Simon Waters (Mar 16)
- Re: FW: DNS TTL adherence Igor Gashinsky (Mar 17)
- RE: DNS TTL adherence Sharad Agarwal (Mar 15)