[dns-operations] DNS version request

[Mukund Sivaraman]

On Wed, Nov 21, 2018 at 04:23:53PM -0500, Andrew Sullivan wrote:
> Yet More Evidence that classes should be deprecated, if you ask me :)

At least with the BIND resolver, classes other than IN aren't going to
work for anything on the public internet except pure forwarding as the
nameserver address database (ADB) also uses the resolver to lookup NS
addresses. The resolver will only query in the class it is configured
for (its view's class), and internet addresses have to be queried with
IN class.

The class field has been around for too long; I don't know if we can
just deprecate it without consequences.

		Mukund