Consider the following scenario. You try to synchronize the time on a multi-homed computer that is running Microsoft Internet Security and Acceleration (ISA) Server 2004. An example of this is a computer that is running ISA Server 2004 together with Microsoft Windows Small Business Server (Windows SBS) 2003 Premium Edition. In this scenario, the time synchronization process is unsuccessful. Additionally, the ISA Server 2004 firewall log file contains the following error message:

This behavior occurs because the Windows time service (W32Time) obtains a list of the IP addresses that are assigned to the computer. Then, W32Time tries to connect to the specified time servers from each IP address until a request is successful or until all tries fail.

When this traffic is sent from an IP address that violates the Windows routing table, ISA Server 2004 blocks these packets. Then, ISA Server 2004 logs the previous error message.