[AusNOG] DNS forwarders (was Re: IPv6: Who's dual stacked? Why don't I look stacked?)

[Yun Huang Yong]

On 8/03/2013 1:13 PM, Paul Gear wrote:
> On 03/08/2013 11:22 AM, Greg McLennan wrote:
>> ...
>> Only thing to be mindfull is to make sure the DNS set in the mikrotik
>> points at a suitable public or ISP's DNS server that can also pass
>> AAAA records.
>
> I've never understood why anyone bothers with upstream DNS forwarders [1].
>
> Are there some strong technical (e.g. customer experiences breakage) or
> community-minded (e.g. the top-level servers can't handle it) reasons
> why we shouldn't just let all DNS queries go to the root? Most people
> seem to set their TTLs pretty low anyway [2], so it seems like a
> pointless exercise.

Performance, at many levels.  How many "globally distributed" DNS 
services actually have name servers in Australia?

I'll take a cache populated by thousands of other users, even if the 
TTLs are 5 minutes, over a cold resolver any day.

Try this to see how it impacts your real life usage:
https://code.google.com/p/namebench/wiki/UsingNameBench

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Query Data Source

namebench works by requesting website addresses from each DNS server. 
This dialog allows you to select where this list of host names are 
generated from. The most accurate data source is your browser history, 
though for smaller histories, the benchmark may bias toward your 
currently configured primary DNS server. "
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