JSI Tip 10439. How do you optimize pass-through authentication of user accounts after you create an external trust between two Microsoft Windows Server 2003 SP1 (Service Pack 1) forests?

Microsoft Knowledge Base Article 916474 contains the following introduction:

You have created an external trust between two Microsoft Windows Server 2003 Service Pack 1 (SP1)-based forests by using fully qualified domain names (FQDN). However, in this case, pass-through authentication of the user accounts in the domain that did not originate the trust (the TARGET domain) may take lots of time. This article discusses how to optimize pass-through authentication after you create an external trust between two Windows Server 2003 SP1-based forests.