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Chapter 1. Prerequisites for establishing a trust

To establish a cross-forest trust between your Identity Management (IdM) domain and an Active Directory (AD) domain, you must correctly configure all required prerequisites on both the IdM server and the AD domain controller.

  • First, read the Planning a cross-forest trust between Identity Management and Active Directory document.
  • AD is installed with a domain controller on it.
  • The IdM server is installed and running.
  • Both the AD server and the IdM server must have their clocks in sync because Kerberos requires a maximum delay of five minutes in communication.

  • Unique NetBIOS names for each of the servers placed in the trust because the NetBIOS names are critical for identifying the AD domain.

    The NetBIOS name of an AD or IdM domain is usually the first part of the corresponding DNS domain. If the DNS domain is ad.example.com, the NetBIOS name is typically AD. However, it is not required. Important is that the NetBIOS name is just one word without periods. The maximum length of a NetBIOS name is 15 characters.

  • The IdM system must have the IPv6 protocol enabled in the kernel.

    If IPv6 is disabled, then the CLDAP plug-in used by the IdM services fails to initialize.

Note

In RHEL 7, synchronization and trust were two possible approaches to indirect integration of RHEL systems to Active Directory (AD). In RHEL 8, synchronization is deprecated and in RHEL 9, it is not available any more. To integrate IdM and AD, use the trust approach instead.

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