Network Ports Used by Active Directory Replication

By default, RPC-based replication uses dynamic port mapping. When connecting to an RPC endpoint during Active Directory replication, the RPC run time on the client contacts the RPC endpoint mapper on the server at a well-known port (port 135). The server queries the RPC endpoint mapper on this port to determine what port has been assigned for Active Directory replication on the server. This query occurs whether the port assignment is dynamic (the default) or fixed. The client never needs to know which port to use for Active Directory replication.

LDAP	389	389
LDAP		636 (Secure Sockets Layer [SSL])
LDAP		3268 (global catalog)
Kerberos	88	88
DNS	53	53
SMB over IP	445	445