You use the firewall client components of Microsoft Internet Security and Acceleration (ISA) Server 2006 on a client. Additionally, you configure the ISA Server 2006 server to log the client host name. However, the firewall log does not contain the "Client Host Name" field.
To resolve this problem, install the hotfix rollup package that is described in the following Microsoft Knowledge Base article:
976301 Description of the ISA Server 2006 hotfix package: October 25, 2009
After you install the hotfix rollup package, the "Client Host Name" field will be included in the ISA Server log for the firewall client.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
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