The principles of DHCP are simple and Microsoft has not changed its core since before Windows NT days, however its not something you shouldn’t undertake lightly or ill-prepared.
Flush DNS command on Windows 8 is the same to DNS flush command on Windows 7, the difference is only in how to open the command prompt.
When a DHCP server registers and updates DNS pointer (PTR) and address (A) resource records on behalf of its DHCP-enabled clients, it uses the information contained within an additional DHCP option: the Client FQDN option (option 81), which permits a client to provide its FQDN and any instructions to the DHCP server that is used to process DNS dynamic updates on its behalf.
The following reasons or events can trigger a dynamic update: When one of these events triggers a dynamic update, the DNS Client service (not the DHCP Client service) sends updates.
Dynamic DNS is a feature that allows hosts to register their records in DNS, thus removing the need for administrators to manually create records.
In addition, Secure Dynamic Update can be required for zones that are Active Directory-integrated (and should be required, per best practices), which allows only members of the Authenticated Users group to register records.