[dns-operations] cache and subnet option

Ralf Weber dns at fl1ger.de
Thu Apr 20 01:43:35 UTC 2017


Moin!

On 19 Apr 2017, at 20:16, Randy Bush wrote:

> dear lazynet,
>
> caching resolver R serves clients on subnets S0 and S1.  a device on S0
> queries for wanna.know.  R queries for the data using the subnet option.
> a device on S1 then queries for wanna.know.  does R respond with the
> cached data from the S0 query, or issue a new query with the S1 subnet
> data?
If S0 doesn't enclose S1 it has to issue a new query and cache that with
the appropriate subnet.

> [ to my naïve eye, issuing a second query would seem to have, shall we
>   say, interesting scaling properties ]
It does and that is why it usually better to get the distribution effect
by placing resolvers near the edge of the network.

So long
-Ralf



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