Can Windows Server 2003 Active Directory ad upgrade directly to Windows Server 2012?
Which Windows Server versions Active Directory ad can upgrade directly to Windows Server 2012?
Windows Server 2003, Windows Server 2003 R2, Windows Server 2008, Windows Server version R2 versions of Active Directory can be upgraded directly to window S Server 2012. Other earlier versions of active Directory, it is recommended that you upgrade to Windows Server 2003 before you upgrade to Windows Server 2012.
To install a read-only domain controller, the domain must have a domain controller that is running Windows Server 2008, Windows Server R2, Windows Server 2012.
In general, in order to follow best practices and practical project implementation experience, low-version Active Directory typically chooses Windows Server 2008 or Windows Server R2 to make a transition before upgrading to Windows Server 2012.
About Active Directory AD upgrade issues