from BIND 8. See use-alt-transfer-source,
alt-transfer-source-v4 and alt-transfer-source-v6.
SECURITY: use-alt-transfer-source is ENABLED unless
you are using views. This may caues a security risk
resulting in accidental disclosure of wrong zone
content if the master supplying different source
content based on IP address. If you are not certian
ISC recommends setting use-alt-transfer-source no;
developer: marka
reviewer: explorer