The protocols that are used by Active Directory replication are described in the following table. RPC and SMTP are the replication transport protocols. LDAP is a directory access protocol, and IP is a network wire protocol. Active Directory Access and Replication Protocols Protocol Description LDAP The primary directory access protocol for Active Directory. Windows Server 2003 family, Windows XP, Windows 2000 Server family, and Windows 2000 Professional clients, as well as Windows 98, Windows 95, and Windows NT 4.0 clients that have the Active Directory client components installed, use LDAP v3 to connect to Active Directory. IP Routable protocol that is responsible for the addressing, routing, and fragmenting of packets by the sending node. IP is required for Active Directory replication. Replication RPC The Directory Replication Service (Drsuapi) RPC protocol, used in the enabling of administration and monitor...