[Samba] DNS Scavenging in Samba AD

[M B]

I read the 4.9 “Features added" release notes about newly available DNS scavenging features, and the problem with domains that were set up in earlier versions of samba AD.

"It is now possible to enable scavenging of DNS Zones to remove DNS records that were dynamically created and have not been touched in some time.”

“This support should however only be enabled on new zones or new installations. Sadly old Samba versions suffer from BUG #12451 <https://bugzilla.samba.org/show_bug.cgi?id=12451> and mark dynamic DNS records as static and static records as dynamic. "

I would really like to enable scavenging of old DNS records, but my domain was set up on version 4.2.3 or some version from that era.

What can I do to prepare my DNS records to enable scavenging? I’ve manually gone through all the host records and ensured that manually created records for servers in the domain are marked as static. However, I’m unsure about SRV records, and other records that are marked with a timestamp but created by Samba AD.

Does the new scavenging feature effect any records in _mcsds.* or _sites.* ?

What is the exact danger to enable scavenging and can I mitigate it through re-creating DNS records using versions 4.9+? 

Thanks