You create a Microsoft Forefront Unified Access Gateway (UAG) 2010 Service Pack 1 (SP1) array.
You enable integrated network load balancing.
You install UAG 2010 SP1 Update 1.
You create an Active Directory Federation Services (AD FS) trunk in the array.
You try to apply the configuration.
In this scenario, you may receive an error message that resembles the following:
Error: Trunk trunk_name cannot be activated due to the following: Invalid External Port address. Please choose a different port.
This problem occurs because the external port number of the trunk is automatically set to 0. Because 0 is an invalid port number, the array configuration cannot be applied.
To resolve this problem, install the service pack that is described in the following Microsoft Knowledge Base article:
2710791 Description of Service Pack 2 for Forefront Unified Access Gateway 2010
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
When UAG SP1 Update 1 is in array mode, the trunk port number is automatically set to 0 regardless of the port number that is configured in the management console. Therefore, the array configuration cannot be applied, and you receive the error message that is mentioned in the "Symptoms" section.
For more information about UAG 2010 SP1 Update 1, click the following article number to view the article in the Microsoft Knowledge Base:
2585140 Description of the Service Pack 1 Update 1 for Forefront Unified Access Gateway (UAG)
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates