Dhcp is not updating dns
When the client dynamically updates its DNS information in this situation, the client's DNS time stamp is not updated until the Refresh interval takes effect.
This behavior controls and manages DNS and Active Directory replication (for AD Integrated Zones).
In the initial stages of the Internet (ARPANET) addressing of hosts on the network was achieved by static translation tables that mapped hostnames to IP addresses.
The tables were maintained manually in form of the host file.
Therefore, only the computer that registered the DNS record can update the DNS record.
When a DNS record is created by a new client, the No Refresh interval is in effect, which is seven (7) days by default.
This process works very well when the correct security permissions are in place for DNS client records.
When a DNS client or a DHCP server performs a dynamic update, the DNS record adds the Client_Computer_Name$ account to the permissions for the DNS record.
It is important to understand how clients update their DNS records dynamically to prevent issues where the process fails due to poor management of your DNS zones and records.
Many DNS administrators find that the Dynamic DNS update process, and aging/scavenging processes may be difficult to understand and manage correctly.