nxdomain not caching for configured reverse lookup

[Mark Andrews]

The forward zone is not for a zone cut in the DNS tree.  As a result
the SOA record is above the "zone" and the SOA record gets ignored.
In practice almost all forwarded zones match a actual zone so the
returned SOA record is accepted.

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org