NOTE: Exchange requires that IP V6 be enabled. Even if you do not use IP V6 you must leave it enabled. During the setup of Active Directory, the Active Directory Setup Wizard will check that both IP v4 and IP v6 have static addresses. As long as the IP v4 address is static you can continue the installation. DO NOT DISABLE IP V6 or else the Exchange Hub Transport Service will not start.
Add role – Active Directory Services
At the Computer Management Screen, press the “Add Roles” link.
At the Select Server Roles dialog, check/tick the option “Active Directory Domain Services”.
See part-2,Category/Exchange 2010
Microsoft exchange server 2010 Step by step Installation | part-2