[dns-operations] cache and subnet option

Mark Andrews marka at isc.org
Thu Apr 20 01:37:31 UTC 2017

In message <m2shl36fq2.wl-randy at psg.com>, Randy Bush writes:
> 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?
> [ to my na=EFve eye, issuing a second query would seem to have, shall we
>   say, interesting scaling properties ]
> randy

It depends on the addresses and the answers.  Yes, ECS has scaling
issues and it depends on the authoritative servers returning the
shortest prefixes possible which in turn depends on ISPs using
sensible addressing plans which keep topologically close clients
under the same prefix.

> _______________________________________________
> dns-operations mailing list
> dns-operations at lists.dns-oarc.net
> https://lists.dns-oarc.net/mailman/listinfo/dns-operations
> dns-operations mailing list
> https://lists.dns-oarc.net/mailman/listinfo/dns-operations
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org

More information about the dns-operations mailing list