Signed-off-by: Josh Soref <2119212+jsoref@users.noreply.github.com>
allows remotes to cache the fact that a domain does not exist and
will not exist for a while. Thanks to Chris Thompson for `pointing
out how tiny our minds
- are <http://ops.ietf.org/lists/namedroppers/namedroppers.2002/msg01697.html>`__.
+ are <https://mailarchive.ietf.org/arch/msg/namedroppers/oqzDiPVjxPuAKqK9IZh9eiEif6w/>`__.
This feature may cause a noticeable reduction in query load.
- Small speedup to non-packet-cached queries, incidentally fixing the
huge memory leak.