[192173] in North American Network Operators' Group
Re: Dyn DDoS this AM?
daemon@ATHENA.MIT.EDU (Eitan Adler)
Fri Oct 21 21:36:16 2016
X-Original-To: nanog@nanog.org
In-Reply-To: <580ABCF7.1030003@vaxination.ca>
From: Eitan Adler <lists@eitanadler.com>
Date: Fri, 21 Oct 2016 18:35:41 -0700
To: Jean-Francois Mezei <jfmezei_nanog@vaxination.ca>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
On 21 October 2016 at 18:12, Jean-Francois Mezei
<jfmezei_nanog@vaxination.ca> wrote:
> On 2016-10-21 18:45, david raistrick wrote:
>
>> switch too..). setting TTLs that make sense for a design that supports
>> change is also easy.
>
> Cuts both ways. Had Twitter had TTLs of say 7 days, vast majority
> wouldn't notice an outage of a few hours because their local cache wa
> still valid.
In practice TTLs tend to be ignored on the public internet. In past
research I've been involved with browser[0] behavior was effectively
random despite the TTL set.
[0] more specifically, the chain of DNS resolution and caching down to
the browser.
--
Eitan Adler
