Multiple Entries In DNS Forward Lookup Zone

Hi,

I have DCHP and DNS running on a Server 2008 R2 Domain Controller. I have noticed multiple entries in DNS with the same IP address but different hostnames. When I check the owner of the entry in DNS one is the DHCP service and the other is a client machine i.e hostname$

The DHCP registered entries are correct and seem to clean up after themselves by removing entries when either the lease expires or is released. The host entries however do not.

I have scavenging/aging of stale records for no-refesh and refresh set to 7 days for all zones, should this possibly be shorter.

Windows clients do have the register this connections addresses in DNS checked in the adapter properties, this must be the default setting.

I suspect reducing the scavenging interval may help but how short is advisable?
I have read else where a GPO to change client NIC properties might also be a solution but that seems a lot of admin. How do others address this issue on the LAN?

As a thought is it possible to restrict the security permissions on the DNS server so that clients don’t have permissions to register themselves leaving DHCP to do it?

Any suggestions welcome, thanks 🙂