The sub-zone can be used to document the device type as server, router, appliance, etc., this provides a well-documented DNS environment.
This also allows manual DNS host records to be easily monitored and maintained.
The two main zones that are used in Active Directory (or Windows Server 2003 and up) are the primary and Active Directory-integrated zones.
You could say that an Active Directory-integrated zone is an improved version a primary DNS zone because it can use multi-master replication to other DNS servers in the domain and use the security features of Active Directory.
Do not use Zone Transfers to IP Addresses An Active Directory integrated DNS Server will replicate the Name Server information to each DNS server.
As DNS servers are added or replaced this information is kept.
A benefit if this type of zone is that it uses the security features of Active Directory.
Stub zones were introduced with Windows Server 2003 and contain only the resource records that are required to identify the authoritative DNS servers for the master zone.
This makes sure that all DNS Zones are available from all DNS servers simplifies administration and prevents name resolution problems Replicating DNS zones across domains will allow all domains in the forest to share DNS information and make (again) administration easier.
As equipment is replace over time easier DNS maintenance is achieved.
Even though the default number of days is set to 7 to scavenge dynamically registered DNS Host records, it is not applied to any zone.
Leaving this to the default setting will speed up DNS queries. This practice also provides a better documented DNS system over time, and keeps PTR records from getting improperly configured with Alias names.
Instead create a sub-zone and create the Host records there and create an Alias (CNAME) record in the appropriate zone.
DNS is an important prerequisite of Active Directory.