chg: usr: Add none parameter to query-source and query-source-v6 to disable IPv4 or IPv6 upstream queries
Add a none parameter to named configuration option query-source
(respectively query-source-v6
) which forbid usage of IPv4 (respectively IPv6) addresses when named is doing an upstream query.
Closes #4981 (closed) Turning-off upstream IPv6 queries while still listening to downstream queries on IPv6.
Edited by Colin Vidal