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Exchange 2010 SP2 CAS Proxying
If any of you considering installing Exchnage 2010 SP2 with RU1 or RU2 or Ru3, the following information is addressed to you.
If your Exchange Organization have many Exchange Servers with CAS roles with different Exchange version, then after upgrade any of CAS server to Exchange 2010 SP2 with RU1 or RU2 or RU3 you can have problems with CAS to CAS proxying.
In scenario where an Exchange 2010 SP2 RU1 Client Access server is proxying to an earlier version of Exchange 2010 or Exchange 2007 Client Access server, then you are affected with a problem to use OWA.
In Event Log you can find errors like:
Event ID: 4999 Log Name: Application Source: MSExchange Common Task Category: General Level: Error Description: Watson report about to be sent for process id: 744, with parameters: E12, c-RTL-AMD64, 14.02.0283.003, OWA, M.E.Clients.Owa, M.E.C.O.C.ProxyUtilities.UpdateProxyUserContextIdFromResponse, M.E.C.O.Core.OwaAsyncOperationException, 413, 14.02.0283.003.
Event ID: 136 Log Name: Application Source: MSExchange OWA Task Category: Proxy Level: Error Description: The sign-in to Outlook Web App failed. User /o=xxxx/ou=xxx/cn=Recipients/cn=testuser has a mailbox on 126.96.36.199 server version. However, no Client Access server or front-end server with a matching version was found to handle the request. For users on Exchange 2007 and above, you can configure the Outlook Web Access URL for redirection using the externalURL parameter on the Exchange /owa virtual directory.
The SP2 RU1 package introduced a change to the user context cookie which is used in CAS to CAS proxying. This cousing a temporary incompatibility between SP2 RU1 or RU2 or RU3 servers and servers running earlier versions of Exchange. The change is such that earlier versions of Exchange do not understand the newer cookie used by the SP2 RUx server.
Below table show Exchange version compatibility in CAS proxying.
Update Exchange versions solves this problem.
|Server proxy||Server being proxied to||Solution|
|Exchange 2010 SP2 RU1||Any version of Exchange 2010 older than SP2 RU1||Apply Exchange 2010 SP2 RU2|
|Exchange 2010 SP2 RU1||Exchange 2007||Apply Exchange 2007 SP3 RU7|