MSExchange OWA 71
This article provides an explanation and possible resolutions for a specific Exchange event. If you don't find what you’re looking for here, try searching Exchange 2010 Help.
Details
Product Name |
Exchange |
Product Version |
14.0 |
Event ID |
71 |
Category |
Proxy |
Symbolic Name |
ProxyErrorAuthenticationToCas2Failure |
Message Text |
Microsoft Exchange Client Access server %1 tried to proxy Outlook traffic to Client Access server %2. This failed because the authentication for the connection between the two Client Access servers failed. This may be due to one of these configuration problems: %n1. The host name in %2 may not be registered as a Service Principal Name (SPN) with Kerberos on the target Client Access server. This usually happens because you used the IP address, instead of the host name, of the target Client Access server in the "internalURL" configuration for the Outlook Web App virtual directory on the target Client Access server. You can change the "internalURL" configuration for the target Client Access server using the Set-OwaVirtualDirectory" task. If you don't want to change the "internalURL" configuration for the Outlook Web App virtual directory on the target Client Access server, you can also use the tool "setspn.exe" on the target Client Access server to register additional SPNs for which that Client Access server will accept Kerberos authentication. %n2.The server hosting %2 may be configured not to allow Kerberos authentication. It might be set to use Integrated Windows authentication for the Outlook Web App virtual directory, but be configured to only use NTLM (not Kerberos) authentication for Integrated Windows authentication. If you suspect this may be the cause of the failure, see the IIS documentation for additional troubleshooting steps. |
Explanation
This error indicates that either Kerberos authentication has been misconfigured on the target Client Access Server or that the target Client Access server has not been configured to allow Kerberos authentication.
User Action
To resolve this error, do one or more of the following:
See the error text for possible causes and resolutions.
Contact a Microsoft Support professional to resolve this issue. To contact a Microsoft Support professional, visit the Exchange Server Solutions Center. In the navigation pane, click Assisted Support Options and use one of the assisted support options to contact a Microsoft Support professional. Because your organization may have a specific procedure for directly contacting Microsoft Product Support Services, be sure to review your organization's guidelines first.
For More Information
If you are not already doing so, consider running the Exchange tools, which have been created to help you analyze and troubleshoot your Exchange environment. These tools can help make sure that your configuration aligns with Microsoft best practices. They can also help you identify and resolve performance issues and improve mail flow. To run these tools, go to the Toolbox node of the Exchange Management Console. To learn more about these tools, see Managing Tools in the Toolbox.