[dns-operations] Google DNS overriding TTL settings?

Noel Butler noel.butler at ausics.net
Thu Sep 13 04:02:55 UTC 2012


On Wed, 2012-09-12 at 16:03 -0500, Chris Boyd wrote:

> Anyone else seeing this?  Or is it common knowledge I just tripped over?
> 
> Was just looking into a DNS issue for a customer and noticed Google's DNS was reporting cache times of 9700+ seconds, despite the zone TTL being 3600 seconds.
> 
> First, an authoritative server, then Google's answers.  Yes, I know Google's answer is different from mine, thus the discovery of the different cache time.
> 
> --Chris


The only way I see them overriding TTL, is using a maximum of 12 hours,
and not what the zone specifies, ie, 24 hours.

Checked a hostname for an IRC server with a TTL of 900 seconds, they
honour that.

-tested on unique hostnames no way in hell google would even know about
they return   xxxxxx   43200	IN	A	xxxxxxx
whereas others  xxxxx 86400    IN      A       xxxxxxx   <-- the correct
one.

so, no big deal really.
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