Most DNS servers have a database for hostname to IP relationships that is similar to the DHCP database. The unmanaged devices that will be used by the managed node must have entries in this database so that machine IP addresses can be found. It is often convenient to document all of the hostnames and IP addresses for the network into the DNS database. This is a fairly routine administrative task and can be done for the entire network and maintained manually as devices are added, moved, or removed. There are many administrative tools that expect DNS information about all network devices, and this makes that information available.
If DDNS updates are being used, the manually maintained portion of the DNS database must be adjusted to avoid conflicts.
There must be DNS entries provided for every device that will be used by the managed node.