When you use the OWA (Outlook Web Access) Forms-Based
Authentication on a Web publishing rule to publish an internal Web site such as
OWA, you cannot use the RADIUS (Remote Authentication Dial-In User Service)
authentication protocol to authenticate a user who logs on to the published
This problem occurs because Internet Security and
Acceleration (ISA) Server 2004 uses Microsoft Windows authentication to
authenticate a user who logs on to the published site that is configured for
OWA Forms-Based Authentication.
Note If you use the RADIUS authentication on a Web publishing rule,
you can no longer use the OWA Forms-Based Authentication to authenticate a user
who logs on to the published site.
To resolve this problem, obtain and install the latest service
pack for ISA Server 2004.
For more information about how to do this,
click the following article number to view the article in the Microsoft
After you install ISA Server 2004 Service Pack 1 (SP1),
enable ISA Server 2004 to use RADIUS authentication for Web publishing rules
that use OWA Forms-Based Authentication. To do this, follow these steps:
Click Start, click Run,
type regedit, and then click OK.
In Registry Editor, locate and then click the following
In the right pane, right-click
OwaAuthenticatesUsingRadius, and then click
In the Value data box, type
0, and then click OK.
Quit Registry Editor.
Restart the Microsoft ISA Server Control
Note This problem has been fixed in Microsoft ISA Server 2004
Enterprise Edition. However, you must follow the steps that are mentioned in
the "Resolution" section of this article to enable ISA Server 2004 to use