Summary: The error UnknownHostException might occur when the Sametime Gateway accesses LDAP or other Gateway servers. Microsoft has released a hotfix for Windows Server 2008 or 2008 R2 that corrects this name resolution problem that can impact Sametime servers running on that platform.
A Lotus Sametime 8.5 Gateway server running on Microsoft Windows 2008 experiences resolving issues. The Sametime Gateway fails to resolve the configured LDAP and the Gateway server address. The error UnknownHostException surfaces when the Gateway server accesses LDAP or other Gateway servers.
This error condition has been identified as a Microsoft Windows problem, documented in the following Microsoft article:
Article ID: 2588507
Title: Error messages may be displayed when a 32-bit application has the /LARGEADDRESSAWARE option enabled in a 64-bit version of Windows Vista, Windows Server 2008, Windows 7, or Windows Server 2008 R2.
To resolve the problem, apply the Microsoft Windows hotfix described in Microsoft article 2588507.
While this problem has not been reported for other Sametime 8.5 components, as a preventive measure, you should apply the hotfix if you run any IBM Sametime 8.5.x server on Microsoft Windows Server 2008 or Windows Server 2008 R2.