Hi, We have a server 2k3 standard (32 bit). It runs IAS and provides RADIUS authentication for a CITRIX Access Gateway (Using Vasco Digipass). Until yesterday @ 11:00am it was running fine. At this time the following windows updates were applied. KB942831 KB2419635 KB982666 KB2124261 KB970483 KB973917-V2 Now, no one can authenticate against the server and We keep getting the following errors each time a user tries to authenticate in the event log: Event Type: Warning Event Source: IAS Event Category: None Event ID: 2 Date: 07/02/2011 Time: 13:26:28 User: N/A Computer: Server01 Description: User User01 was denied access. Fully-Qualified-User-Name = Domain\User01 NAS-IP-Address = xxx.xxx.178.2 NAS-Identifier = <not present> Called-Station-Identifier = <not present> Calling-Station-Identifier = <not present> Client-Friendly-Name = CAG Client-IP-Address = XXX.XXX.XXX.178 NAS-Port-Type = Async NAS-Port = 0 Proxy-Policy-Name = Use Windows authentication for all users Authentication-Provider = Windows Authentication-Server = <undetermined> Policy-Name = <undetermined> Authentication-Type = PAP EAP-Type = <undetermined> Reason-Code = 16 Reason = Authentication was not successful because an unknown user name or incorrect password was used. Any ideas on how to get this to work again? Thanks in advance Mark

Hi, Please refer to the following articles to troubleshoot the issue: 802.1x client authentication fails when you connect to a Windows Server 2003-based computer that is running IAS http://support.microsoft.com/kb/838502 Troubleshooting IEEE 802.11 Wireless Access with Microsoft Windows http://technet.microsoft.com/en-us/library/bb457017.aspx Event ID 2 Source IAS http://www.eventid.net/display.asp?eventid=2&eventno=1376&source=IAS&phase=1 If the issue persists, I also would like to suggest you uninstall the recently installed updates one by one to find out the root case. Regards,Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.