Re: Issue: PTR RR queries for 254.169.in-addr.arpa

[There's another message from me to this list on this subject waiting
 in a moderation queue somewhere, oh well.]

There's one thing missing from Stuart's picture here: in cases where
the load from these queries on a recursive name server is significant,
it's less expensive (in terms of resources consumed) for the recursive
name server to answer with RCODE 3 than for the name server just to
drop the queries.  An RCODE 3 error will cause the client to shut up,
while dropping the query will cause the client to retransmit.

I think there's a compromise position here:

- Clients MUST NOT expect recursive name servers to answer these
  queries.

- Recursive name servers MUST NOT allow these queries to escape the
  local scope.

- Recursive name servers MAY reply with RCODE 3 for their own reasons.