Understanding When to Create a Realm Trust
Applies To: Windows Server 2008, Windows Server 2008 R2, Windows Server 2012
When to create a realm trust
You can establish a realm trust between any non-Windows Kerberos version 5 (V5) realm and an Active Directory domain. This trust relationship allows cross-platform interoperability with security services that are based on other versions of the Kerberos V5 protocol, for example, UNIX and MIT implementations. Realm trusts can switch from nontransitive to transitive and back. Realm trusts can also be either one-way or two-way.
For information about how to create a realm trust, see Create a Realm Trust.