On a computer that is running Microsoft Internet Security and Acceleration (ISA) Server 2006 or ISA Server 2004, you edit the Directly access these servers or domains list for a network in the ISA Server Management console. However, existing IP address entries in the list may disappear from the list after you try to add or modify an entry.

This problem occurs only when you try to add overlapping IP address ranges in the Directly access these servers or domains list.

This problem occurs because the ISA Server Management console unexpectedly removes some entries from the Directly access these servers or domains list after you cancel an operation that tries to add some invalid IP address ranges.

Before you click Apply in the network properties dialog box, check the Directly access these servers or domains list again to make sure that the IP address ranges do not overlap.

If you have already clicked Apply after you added overlapping IP address ranges, do not save the changes. Instead, click Discard to discard all changes that have been made.

Note You will lose all changes that have been made since the last time changes were successfully saved. For example, if you added a new access rule before you edited the Directly access these servers or domains list, the new access rule will also be discarded.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.