[dns-operations] About open DNS resolvers

[John Kristoff]

On Thu, 23 Aug 2012 09:18:37 +1000
Mark Andrews <marka at isc.org> wrote:

> It is an open resolver.  It doesn't matter if it does the lookup
> directly or indirectly.  It is honoring the "rd" bit and supplying
> recursive service.

It is worth noting this distinction for measurement studies.  I, and
others probably have as well in the past, have examined only what was
ultimately fetching the answer from an authoritative server.  If you
are also not examining the actual answered returned to the original
query source, your measurement results may not accurately reflect
reality.

John