JSI Tip 7418. When you promte a member server to a domain controller in a new domain, its' original DNS zone name remains unchanged?

If a member server in domain A uses a static IP address, and you promote it to a domain controller in domain B, the original DNS zone name must be manually reset in the DNS properties of the adapter.

See the following Microsoft Knowledge Base articles:

214677- Automatic Detection of Site Membership for Domain Controllers.

195242 - Cannot Change Computer Name of a Domain Controller.