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Exchange 2010 SP2 RU1 and CAS-to-CAS Proxy Incompatibility

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The_Exchange_Team
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Feb 17, 2012

Update 04/23/12: we have updated this blog post to indicate that fixes for this issue have been released. Please see below table or our announcements for release of Exchange 2010 SP2 RU2 and Exchange 2007 SP3 RU7

We wanted to give you a heads up regarding a change in CAS to CAS proxy behavior between servers running Exchange 2010 SP2 RU1 and servers running older versions of Exchange.

The SP2 RU1 package introduced a change to the user context cookie which is used in CAS-to-CAS proxying. An unfortunate side-effect is a temporary incompatibility between SP2 RU1 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 RU1 server. As a result, proxying from SP2 RU1 to an earlier version of Exchange will fail with the following error:

Invalid user context cookie found in proxy response

The server might show exceptions in the event log, such as the following:

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.

Not all customers are affected by this. But since we received a few questions about this, we wanted to let you know about the change. Many Exchange customers do not use proxying between Exchange 2010 and Exchange 2007 but rather use redirection, which is not affected by the change. However, if you are using CAS-to-CAS proxying, 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 by the change.

If you are affected after application of Exchange 2010 SP2 RU1, please see the below table for the solution to this problem.

Server proxy versionServer being proxied toAction to take (updated!)
Exchange 2010 SP2 RU1 Any version of Exchange 2010 older than SP2 RU1 Apply Exchange 2010 SP2 RU2, as announced here.
Exchange 2010 SP2 RU1 Exchange 2007 Apply Exchange 2007 SP3 RU7, as announced here.

The Exchange Team

Updated Jul 01, 2019
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Exchange 2007
Exchange 2010
  • Deleted's avatar
    Deleted
    Feb 18, 2012

    Where can I download the E2007 IU ?

  • Deleted's avatar
    Deleted
    Feb 18, 2012

    @Qwerty - please call into support to obtain.

  • Deleted's avatar
    Deleted
    Feb 18, 2012

    Thanks for the update  .  Why exchange Product team QA  didnt test   properly  for all scenarios ?

  • Deleted's avatar
    Deleted
    Feb 18, 2012

    @qwerty: In general, interim updates are only available by calling support.

    We'll announce when this IU for Exchange 2007 is avaialble. The post has been updated.

  • Deleted's avatar
    Deleted
    Feb 18, 2012

    Any reason for the changes on CAS-CAS proxy @2010 SP2 RU1...?

  • Deleted's avatar
    Deleted
    Feb 18, 2012

    Am I right that OWA CAS-to-CAS proxying was always possible only if SP and RU levels are exactly the same on the proxying CAS and on the CAS to which it is proxying? And if yes, then what is the meaning of this article?  Maybe this SP2 RU1 feature will break proxying for ActiveSync (which works when SP and RU levels are different as opposed to OWA proxying)?

  • Deleted's avatar
    Deleted
    Feb 19, 2012

    Just to make shure - a combination of Webmail of Exchange 2010 and 2003 is not affected?

  • Deleted's avatar
    Deleted
    Feb 19, 2012

    @Karsten: 2010 is not capable of proxying OWA to 2003. It always redirects.

  • Deleted's avatar
    Deleted
    Feb 20, 2012

    @ Andrey - CAS is normally able to proxy to older versioned CAS accross AD sites. So SP1 can proxy to RTM for example. However withthis change we have moved the lowest version we will proxy to, to equal the version installed on the calling CAS. So now it's SP2 RU1 > SP2 RU1 minimum. With the next RU2 that should not change (though as with all these things, we may need to for some reason), so then SP2 RU2 > SP2 RU1 should work ok.

    And this change only affected OWA. So no impact to ActiveSync.

  • Deleted's avatar
    Deleted
    Feb 20, 2012

    So with RU2 I see that RU2-RU1 proxying will work. But will proxying from Exch 2010 SP2 RU2 to Exchange 2007 (or versions below Exch 2010 SP1 RU1) also work?

    We plan to use CAS-CAS proxying between Exch 2010 and Exch 2007 until we migrate off of Exch 2007.

    So we would like to know if we HAVE to plan for the IU on Exch 2007 or whether RU2 will restore this backward compatibility in proxying. Thanks in advance.