Single-label Domain Names and Exchange Server 2007 SP1 (Part Deux)


EDIT 03/26/08: Please see our later post on this subject for the location of updated prerequisite check XML file.

Summary

This is a follow-up to an earlier post: Single-label Domain Names and Exchange Server 2007 SP1. Please refer to it for background information on this issue.

After investigating Exchange 2007 Service Pack 1 installed in an Active Directory domain with a Single-label Domain (SLD) name, Microsoft has changed the Setup prerequisite rule for SLDs from an Error to a Warning, thereby allowing Service Pack 1 installation to continue in SLD environments.

There are a few items that I want to point out:

  • Not a recommended configuration
    While Exchange 2007 SP1 is supported with SLDs, the Exchange product team's view is that SLDs are not a recommended configuration. While we will allow installation of Exchange 2007 SP1 in an SLD, we strongly recommend that you take step to move your organization out of this configuration.
  • Not fully tested
    Exchange 2007 and Exchange 2007 SP1 have not been fully tested in SLDs. The Exchange team investigated known issues and determined that there were sufficient workarounds to safely allow installation of SP1 to continue; however, there may be unknown issues that could arise from operating Exchange 2007 in an SLD environment.
  • Deprecated in the next version of Exchange
    The next version of Exchange will not support Active Directory domains with single-label domain names. Similarly, upgrades of Exchange servers currently deployed in single-label domains will not be supported. In this case, "next version" means the next major release of Exchange Server. Customers that intend to deploy the next version of Exchange must use fully qualified domain names.
  • Documentation being updated
    Currently, the existing TechNet documentation states that SLDs are not supported in Exchange 2007. We are working to change the documentation to reflect that SLDs are supported but not recommended configurations. The updated documentation is expected to be published on TechNet as part of the March 2008 document refresh in early March.
  • Exchange 2007 does not support Domain Rename, and there are currently no plans for a Domain Rename Fixup Tool for Exchange 2007
    The possibility of creating a domain rename fixup tool for Exchange 2007, similar to the one that was written for Exchange 2003, was discussed internally. The decision is that there will not be a similar tool written for Exchange 2007. The Domain Rename Fixup tool written for Exchange 2003 is not compatible with Exchange 2007, and should not be used in Exchange 2007 environments.

Recommendations

We have the following recommendations for customers who have Exchange installed in an SLD.

If you have Exchange 2003 installed in an SLD, and you have not run any Exchange 2007 Setup /prepare switches yet:

If you have Exchange 2003 installed in an SLD you should change your domain name to a fully qualified domain name (FQDN).

Exchange 2007 RTM is installed and you want to migrate to a supported configuration:

If you want Exchange 2007 deployed in a fully supported configuration, then you have two options:

  • Migrate users, computers, and security groups from your SLD to a new domain with a fully-qualified domain name in the same Active Directory forest
  • Migrate users, computers, and security groups from your SLD to a new domain with a fully-qualified domain name in a different Active Directory forest

Please note that if you have already installed Exchange 2007 into the organization containing Exchange 2003, or if you have already run the Exchange 2007 /prepare setup switches, you cannot perform a domain rename even if Exchange 2007 servers are removed from the organization. That is because Exchange 2007 setup creates new Active Directory objects which will not be properly renamed by the Exchange 2003 domain rename fixup script.

How SP1 Setup is Being Changed

Microsoft is changing the Single-label domain pre-requisite check from an Error, which blocks Setup, to a Warning, which cautions you strongly, but allows Setup to proceed. While the exact wording has not been determined, it will be similar to the following: "Setup has determined that this computer belongs to a domain that has a single-label DNS name. This is not a recommended configuration. You should plan to migrate to a fully-qualified domain name. ". We'll inform you when this rule has been changed, and when the update is available for download.

If you are installing Exchange 2007 SP1 from files on the local computer, and the computer is connected to the Internet, Setup will automatically download the new rule when it is available.

In addition to the prerequisite rule change, we're also going to modify the ExBPA Health Check rule to mirror the modified Setup check.

Known Issues and Workarounds

Some other things that you should be aware of include:

Installing from DVD
If you are installing Exchange 2007 SP1 from a DVD, Setup will not download the new rules. In this scenario, you must copy the Setup files to your local computer and then run Setup from those local files. This allows Setup to download new rules.

Computer not connected to Internet
If your computer is not connected to the Internet, it won't be able to download the new ExBPA rules. To workaround this, Microsoft will make the updated XML file available for download. Customers will need to download the update and then manually update their local installation files. Details on how to obtain the new XML file will be announced at a later date.

Autodiscover won't create profiles correctly without a hierarchical address
This issue should only apply to customers that are only sending mail internally; anyone who is routing mail externally should have encountered and resolved this issue. Outlook assumes that the default Email Address Policy (EAP) would be to a publicly resolvable name.  To send mail on the Internet, SMTP domains in an EAP must resolve to one of the top level domains supported by RFC's.  The technical requirement for Outlook to work is that the EAP represents at least two levels of hierarchy in the name, i.e. it must have at least one dotted suffix.  The following would be examples of names that Outlook would consider valid:

  • contoso.com
  • contoso.eu
  • contoso.test

The thing to note here is that although Outlook will consider contoso.test to be a valid domain name, it is not publicly resolvable according to RFC standards because there is no top level domain called ".test" on the Internet.  Such a domain name could be used internally, however, mails would only route internally.  It would not be possible to receive mail for that domain from outside the company.

To maintain your SLD, your default EAP must be set to include at least two levels of hierarchy, for example:

Fname.Lname@contoso.com

If you have a mixed environment of Exchange 2003 and Exchange 2007 the EAP is probably the Exchange 2003 version and won’t have the opath filter syntax, therefore run both of the following cmdlets in order.  If you have a pure Exchange 2007 environment just run the second cmdlet:

Set-EmailAddressPolicy "Default Policy" -IncludedRecipients AllRecipients

And then:

Set-EmailAddressPolicy "Default Policy" -enabledPrimarySMTPAddressTemplate "%g.%s@contoso.com"

Domain Rename - best option (if you can use it)

Microsoft strongly recommends that you move off of your single-label domain and transition to an Active Directory domain with a fully qualified domain name. Some of the other challenges with this configuration include:

  • Windows member servers and domain controllers joined to single-label domains require additional configuration to dynamically register or resolve DNS records in single-label DNS zones
  • Some server-based applications are not compatible with single-label domain names. Application support may not exist in the initial release of an application, or may be dropped in a future revision
  • Some server-based applications are not compatible with the domain rename feature supported by Windows Server 2003 and Windows Server 2008 domain controllers. Such incompatibilities either block or complicate the use of domain rename when trying to adopt a fully-qualified domain name. Examples of applications that are not compatible with domain rename include but are not limited to Microsoft Exchange 2000 Server, Microsoft Exchange Server 2007, ISA 2004, Live Communications Server 2005, Microsoft Operations Manager 2005, Microsoft SharePoint Portal Server, and Microsoft SMS 2003.
  • There is no technical reason to create Active Directory domains with single-label DNS names. Because of the above, Windows Server 2008 DCPROMO warns (but does not hard block) against the creation of new domains with single-label domains.
Resolve two problems at one time

Microsoft would like to take this opportunity to make an additional suggestion to customers who fit both of these criteria:

  • You have Exchange 2007, either RTM or SP1, installed in an SLD and you envision wanting to upgrade to a future version of Exchange,

and

  • You have Exchange 2003 or Exchange 2007 installed on Windows Server 2003, and you envision wanting to upgrade to Windows Server 2008.

Customers who fit both of these criteria face two upgrades, both of which call for the removal of Exchange 2007 prior to continuing.

  • In-place upgrade of the operating system on an Exchange Server from Windows 2003 to Windows 2008 is not supported. In order to do an in-place upgrade the operating system of an Exchange server to Windows 2008, you must completely remove Exchange and some of its dependencies prior to the installation.
  • You can't rename a domain with Exchange 2007 installed.

We suggest that you plan your next operating system and Exchange Server upgrades to resolve both of these issues at the same time by either migrating objects to a new domain with a fully qualified domain name, or by performing a domain rename of your existing domain.

- Ed Beck


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Comments (50)
  1. Tony Bunce says:

    This post really sends mixed messages.

    It says that renaming a domain is the best migration path, but there will never be a rename tool for exchange 2007. Migrating to a new forest is a much more complicated process than a rename, but it looks like we are being forced in that direction.

    In the last section ("Resolve two problems at one time") you say that the best option is to remove exchange 2007 and then rename the domain, but in the top part of the post you say "you cannot perform a domain rename even if Exchange 2007 servers are removed from the organization".  And if you remove exchange 2007 where does all the mail box data go?

    Basically we have all waited a month just to find out we can now install SP1 but that is just delaying the inevitable migration that we have all feared.  Why can’t we get a rename tool for 2007 to make our lives easier?

  2. iamme says:

    What’s up with this:?

    # Migrate users, computers, and security groups from your SLD to a new root domain with a fully-qualified domain name in the same Active Directory forest

    # Migrate users, computers, and security groups from your SLD to a new root domain with a fully-qualified domain name in a different Active Directory forest

    Exchange 2007 doesn’t "have to be" in a root domain.  You can have an empty root with a child domain or another tree and install Exchange there as long as PrepareForest and PrepareAD have been run in the forest root.  You can then do PrepareDomain on the child/tree domain and install Exchange there.  Why are you saying you have to migrate everything to a root domain?

  3. Andy.Hardin says:

    Thanks for the information, Ed.  It looks like we’re going to have to migrate to a new domain, especially since we’re not having problems with FCS due to the SLD.  With the recent release of Server 2008, it seems like a good time.

    I’ll be looking at the Server 2008 info, but is there any good documentation you can point us to for migrating an organization to a new domain?

    Thanks,

    Andy

  4. Exchange says:

    iamme,

    You are right, that was a typo, fixed that. Thanks for letting us know!

  5. Mike Crowley says:

    This is great!  Thanks for listining to us.  Most of us realize this isnt a good idea, but have adopted enviroments where it was already installed.  The biggest problem was that it let us get RTM installed in the first place.  If there was more focus here I dont think as many people would have complained.  I think disallowing it in the next version is a great idea.  Just as long as its before any installation can take place.  We were all just very surprised when sp1 came out.

    :)

  6. jc says:

    Yes, thanks much for listening to us.  I was pretty damn close to renaming before you posted up on technet.  Just curious, do you have any idea when the update will be released?

  7. Chris says:

    Hello guys, any information about the "NEW" SP1 release ?

  8. jwdberlin says:

    I’m not shure how to interprete this. Is it possible to rename the domain after removing Exchange 2007 or not?

  9. Exchange says:

    jwdberlin,

    If you have other servers in your org (E2000/E2003) then removing Exchange 2007 will not be sufficient. If you have a simple org (let’s say one or two E2007 servers) – then removing E2007 will in fact remove your org out of AD, in which case you can go with domain rename process after E2007 removal.

  10. Devon says:

    Any word on when the change to the setup will actually occur.  I ran this in test this weekend and SLD is still flagged as an error.

    On a separate note, "setup.com /m:recoverserver" does not work, even with the RTM version of Exchange when in a SLD.  Setup gives an error that Exchange is in a SLD and does not continue.  This kinda blows a hole in our DR procedures, as we cannot recover Exchange servers currently in production using the recoverserver option.  ;-)

    Looking forward to moving to SP1 and thanks for providing us a solution for moving forward.  

  11. EdBeck says:

    The updated XML file will be available in March.

  12. jwdberlin says:

    Ed,

    thanks for this quick reply. We have a quite simple org but with one old 2003 and one 2007 which holds about everything. We do not need the 2003 server in the future. Still a chance for renaming?

  13. EdBeck says:

    Devon – What’s happening is that when you run Setup it’s going out and getting the new rules.  When Setup does that it’s getting the new file with the block.

    Have you tried to recover Exchange 2007 RTM from an RTM DVD?

  14. EdBeck says:

    jwdberlin,

    Since you have already installed Exchange 2007 into the organization containing Exchange 2003 (or if you have already run the Exchange 2007 /prepare setup switches), you cannot perform a domain rename even if Exchange 2007 servers are removed from the organization. That is because Exchange 2007 setup creates new Active Directory objects which will not be properly renamed by the Exchange 2003 domain rename fixup script.

    Please refer to the "Removing Servers from a Coexistence Scenario" section in the TechNet topic "Removing and Modifying Exchange 2007"  http://technet.microsoft.com/en-us/library/aa998193(EXCHG.80).aspx

    Thanks,

    Ed Beck

  15. Eric says:

    I still error out as a SLD? Has this fix not happend yet?

  16. T McNutt says:

    If you can help I have some specific questions about my clients domain.

    It now is a 2003 domain with a 2000 exchange server.  I have installed a 2007 exchange but have not moved any mail boxes or folders.  The single label domain names came up as I was trying to install sp1 on exchange 2007.  My client has a sld now but is ready to rename the domain.  Can I uninstall the 2007, rename the domain and reinstall 2007?  If not can you recommend a plan of action.  FYI the 2000 exchange manager shows only the 2000 server.  The 2007 manager shows legacy mailboxes.

    Any help would be appriciated.

  17. EdBeck says:

    Eric,

    The updated XML will be available in March.  I’ll post an update to this thread when it’s avaialble.

    Ed Beck

  18. EdBeck says:

    T McNutt,

    Since your’re in a coexistence scenario you’ll need to do more that remov Exchange 2007 before the domain rename.

    Please refer to the "Removing Servers from a Coexistence Scenario" section in the TechNet topic "Removing and Modifying Exchange 2007"  http://technet.microsoft.com/en-us/library/aa998193(EXCHG.80).aspx

    Thanks,

    Ed Beck

  19. Desmond Lee says:

    How about this scenario: 1 or more AD forests that have been setup with a SLD forest root and multiple child domains (e.g. corp, ch.corp, it.corp, fr.corp) with no Exchange setup and a brand new Exchange 2007 resource forest with proper FQDN  such as e2k7rd.eu?

    With this work without problems, with or without Exchange Server 2007 SP1?

    Thanks!

  20. Martijn says:

    Ed,

    I get confused about the domain remaning options:

    Your answer to T McNutt: Since your’re in a coexistence scenario you’ll need to do more that remov Exchange 2007 before the domain rename.

    Your answer to jwdberlin: Since you have already installed Exchange 2007 into the organization containing Exchange 2003 (or if you have already run the Exchange 2007 /prepare setup switches), you cannot perform a domain rename even if Exchange 2007 servers are removed from the organization.

    In a coexistence scenario with Exchange 2000/2003: is it possible to rename an AD domain after removing Exchange 2007 Servers included new Active Directory objects created by Exchange 2007 setup?

  21. Eric says:

    Thanks Ed.

  22. EdBeck says:

    Desmond Lee,

    Exchange 2007, either RTM or SP1, is supported in an environment in which Exchange is installed in an FQDN child domain of an SLD root domain.

    The key is does your default EAP specify a hierarchical address or not.  If your default EP does not specify a hierarchical address please see the “Autodiscover won’t create profiles correctly without a hierarchical address” section of this blog.

    As to “will this work without problems” please remember that Exchange 2007 and Exchange 2007 SP1 have not been fully tested in SLDs. The Exchange team investigated known issues and determined that there were sufficient workarounds to safely allow installation of SP1 to continue; however, there may be unknown issues that could arise from operating Exchange 2007 in an SLD environment.

    Ed Beck

  23. EdBeck says:

    Martijn,
    Renaming a domain with Exchange 2000/2003 installed is not possible, regardless of if Exchange 2007 has been installed or not.  Some of the Exchange Domain Rename Fixup tool requirements are:

    The following conditions are the prerequisites for using the Windows Server 2003 domain rename tools and XDR-fixup.exe:

    • Windows Server 2003 is required   All domain controllers must be running Windows Server 2003, and the Active Directory functional level must be set at the Windows Server 2003 level. More information about forest functional levels is available in the Windows
    domain rename tools documentation and Windows Server 2003 documentation.
    • Exchange Server 2003 SP1 is required   The domain rename tools are supported in Exchange Server 2003 SP1. All Exchange servers in the organization must be running Exchange Server 2003 SP1.

    • Exchange 2000 Server and Exchange Server 5.5 are not supported   The Rendom.exe and XDR-fixup.exe tools are not supported in Exchange Server 2003 without SP1, Exchange 2000 Server, or Exchange Server 5.5. If the Rendom.exe tool detects Exchange 2003 servers
    that do not have SP1 installed or if it detects Exchange 2000 servers, the tool will not proceed.

    There are more prerequisites, please download the Exchange Domain Rename Fixup tool from

    http://www.microsoft.com/downloads/details.aspx?familyid=24b47d4a-c4b9-4031-b491-29839148a28c&displaylang=en and see the “Prerequisites” section for more.

    I apologize if I’ve caused confusion by my use of the word “coexistence”.  I was referring to coexistence between Exchange 2003 and Exchange 2007.  If Exchange 2007 has been installed into an organization containing Exchange 2003, or if you have already run
    the Exchange 2007 /prepare setup switches, you cannot perform a domain rename even if Exchange 2007 servers are removed from the organization. That is because Exchange 2007 setup creates new Active Directory objects which will not be properly renamed by the
    Exchange 2003 domain rename fixup script.

    Please refer to the TechNet article “How to Completely Remove Exchange 2007 from a Server”

    http://technet.microsoft.com/en-us/library/bb123893.aspx for more information.

    Ed Beck

  24. T McNutt says:

    After reviewing the responses and comments I am at a loss what to do. As I understand the comments so far…

    If Exchange 2007 was not happy with my SLD, why did it allow me to install it and move forward with my migration?  It would have been advantageous to have Exchange 2007 post an error before I proceeded with the install, or even stop the install completely.  Not all clients upgrade at every release.  We find that the 4 to 5 years time frame is the normal upgrade times.  I now have zero options.  I cannot rename the domain because of “If Exchange 2007 has been installed into an organization containing Exchange 2003, or if you have already run the Exchange 2007 /prepare setup switches, you cannot perform a domain rename even if Exchange 2007 servers are removed from the organization. That is because Exchange 2007 setup creates new Active Directory objects which will not be properly renamed by the Exchange 2003 domain rename fixup script.”  I have done this with 1 exception, I have an Exchange 2000

    Where do I go from here?  My client has trusted me to make the correct IT decisions for them and now I have placed my client in a position where they cannot upgrade because they their new mail server is incompatible with their old.  Microsoft is now punishing my client for their desire to move forward with Exchange 2007.  The amount of time spent on this already is absurd and nothing has been done to move the process forward.

    Please help me to understand this situation and if I have misunderstood any of this,  please respond.

  25. KnacK says:

    This is nuts!

    If this was documented I would never have installed Ex2k7 to begin with and would have done a rename first.

    Reviewing the technet article solves nothing.  Removing ex2k7 and all reminents also removes ex2k3 which I currently have.

    As an SMB, this really hurts.  I’ve had this infrastructure in place since 3.51.

    I truely hope there will be a resolution, preferably in a renaming too for ex2k7 as there was for ex2k3.

  26. EdBeck says:

    T McNutt,

    You are correct that you are not able to rename the domain now that Exchange 2007 has been installed on the SLD.  

    However you will be able to upgrade to Exchange 2007 SP1 as soon as we have changed the rule from blocking the installation to warning about the presence of an SLD.  We expect the rule to be modified in the March update.  When the updated rules are available I’ll post a notification on this blog.

  27. KnacK says:

    First off,

    Ed, thanks for keeping us up to date on this.

    Now, in my scenario, since I do have ex2k3 and a fresh install of ex2k7, I should be able to follow the MS article about completely removing exchange from the organisation, do my domain rename, then reinstall at least ex2k3. ( of course doing a complete mail backup before all of this)

    Sound reasonable?

  28. EdBeck says:

    KnacK,

    Yes, the scenario that you describe (completely remove Exchange 2007 from your organization) will allow you to rename your domain.

    Just to make sure that we’re all looking at the same page, the topic "How to Remove an Exchange 2007 Organization" is located at http://technet.microsoft.com/en-us/library/aa998313(EXCHG.80).aspx.  This page has addional references.

  29. wallew says:

    All that money and all that talent at MS and MS cannot provide a domain rename tool for these guys?  Hmmmm…

  30. wallew says:

    All that money and all that talent at MS and MS cannot provide a domain rename tool for these guys?  Hmmmm…

  31. KnacK says:

    Ed,

    Just so I am clear on this:

    I currently have all of my mailboxes on ex2k3.  My ex2k7 server is idle.

    If I remove ex2k7 per the process above, I will still retain my ex2k3 server and then be able to rename my domain?

    Or will I have to also remove my ex2k3 server as well?

    Removing my ex2k7 server won’t be a problem if I can retain my ex2k3 server.

    Chris

  32. MK says:

    Just curious is that the update that will allow SP1 to be installed on SLD available yet? Any ETA

    Thanks

    MK

  33. Ed Beck says:

    MK,

    The updated files will be avaialble by md-March.

    Ed Beck

  34. Ed Beck says:

    KnacK, there is something we are clarifying on this scenario, will post the answer at the later time.

    Ed Beck

  35. AndrewRobinson says:

    Can anyone tell me if MS are working on a program to rename a domain once Exchange 2007 has been installed if you currently have a single lable domain?

  36. KnacK says:

    Thanks Ed,

    I look forward to your update.

    Chris

  37. Ed Beck says:

    Exchange 2007 does not support Domain Rename, and there are currently no plans for a Domain Rename Fixup Tool for Exchange 2007

    The possibility of creating a domain rename fixup tool for Exchange 2007, similar to the one that was written for Exchange 2003, was discussed internally. The decision is that there will not be a similar tool written for Exchange 2007. The Domain Rename Fixup tool written for Exchange 2003 is not compatible with Exchange 2007, and should not be used in Exchange 2007 environments.

  38. BW says:

    Has this been released?  The Microsoft dwonloads webpage has the date published as 3/6/08 and nobody has posted on here since 3/6/08.

  39. Exchange says:

    BW,

    We are looking to release English in about a week, with other languages following few weeks after that. We’ll post something when this happens.

  40. Jasen says:

    OK Ed – I have read and re-read and I read a lot of circular logic here. Simply put – I have a single Exchange 2007 Server. If I can backup the mailboxes to PST files (EXMerge) – Remove the server – Remove the Exchange 2007 from the organization using the technet article – can I then do a domain rename – then reinstall Exchange 2007 and reimport mailboxes?

  41. Ed Beck says:

    Jasen – Yes. Completely removing the Exchage Organization, performing the domain rename, and then reinstalling Exchange 2007 will work.  

  42. jasenwalker says:

    Ed – I think I might just kiss you (In A Manly way!) – thanks for the help and a quick response!

  43. Andy L says:

    Ed – Do you know the release date?  March is moving by quickly.

  44. Ed Beck says:

    Testing on the new file is not quite finished.  I have a new ETA of next Thursday March 27th.  

  45. Rakesh says:

    Can we rename a SLD with domain rename tood before installing exhcange 2007 ?  I mean  SLD forest without any version of exhcange installed.

    Renamed SLD with domain rename tool and then install Exchange 2007 sp1. Is it supported scenario ?

  46. Ed Beck says:

    Rakesh,

    Yes, renaming the domain without any versions of Exchange installed, and then installing Exchange 2007 is a supported scenario.

  47. Ness says:

    We have SLD, Exchange 2000, a 2000 DC and a 2003 DC. We want to rename SLD, upgrade the 2000 DC to 2003 and upgrade to Exchange 2007. What is the best plan of attack? Thanks.

  48. Ed Beck says:

    There is a new post:

    "Update that will allow you to install Exchange 2007 SP1 into a Single-label named domains is now available" located at http://msexchangeteam.com/archive/2008/03/26/448511.aspx

  49. Ed Beck says:

    Ness,

    Please refer to this document for information on upgrading to Exchange Server 2007 from multiple environments.

    http://technet.microsoft.com/en-us/library/bb124008.aspx

    Also, please note that Domain Rename was introduced in Windows Server 2003.

  50. Ed Beck says:

    KnacK,

    After trying your scenario out, thanks Nino, we’ve determined that if you’ve ever had Exchange 2007 in your environment or you ran the Exchange 2007 /prepare setup switches, you’ll need to completely remove the Exchange organization, including earlier versions, before renaming your domain.  If you do not remove your entire Exchange organization, your Exchange 2007 re-installation will fail.

    So again – removing all of Exchange 2007 servers is not going to be enough. This is because the XDR-Fixup script does not know about many objects that Exchange 2007 creates and therefore does not rename them properly.

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