Details about the process that occurs when you use LDAP in Intelligent Application Gateway (IAG) to connect to Active Directory

This article contains details about the process that occurs when you use Lightweight Directory Access Protocol (LDAP) in Intelligent Application Gateway (IAG) to connect to the Active Directory directory service.

The standard LDAP operation in a Microsoft Windows environment involves additional APIs (when compared to a non-Microsoft LDAP environment) to achieve security, robustness, and a scalable solution to lots of Active Directory deployments. These Active Directory deployments include security settings, trust relationships, global cataloging, and group membership fetching.

In theory, you can connect to Active Directory by using only LDAP APIs. However, we do not recommend this approach because of the lack of security and scalability that it involves.

The following is a list of the ports and APIs that are used directly or indirectly by IAG during a standard user authentication and authorization session:

• Port 88: Kerberos/TCP
  
  This is used for Kerberos authentication (SSPI/Negotiate).
• Port 53: DNS
  
  This is used for DNS queries.
• Port 138: NETBIOS UDP
• Port 139: NETBIOS TCP
• Port 135: Remote procedure call (RPC)
• Port 445: Direct hosting of SMB/TCP
  
  This is used for LSA management functions.
• Port 389: LDAP
• Port 636: Secure LDAP
• Port 3268: Global catalog
• Port 3269: Secure global catalog
• Port 1024-5000: RPC

Note The IAG out-of-the-box implementations of Lotus Notes Directory and of Netscape LDAP Server use only LDAP APIs. Additionally, these implementations use port 389.

For more information about the Windows LDAP implementation, see the "Understanding LDAP" white paper. To download this white paper, visit the following Microsoft Web site:

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.