Removing Edge Subscription When Exchange 2013 Installed

Exchange 2013 does not have an Edge role (at the time of writing – Aug 2013). It is possible to use Exchange 2010 SP3 and install the Edge role should you need one.

There is a problem though when it comes to removing the Edge Subscription between an organization that contains Exchange 2013 servers and the Exchange 2010 Edge Server. To remove the subscription on the Edge server role you run Remove-EdgeSubscription servername and this removes both the subscription and any subscribed objects from the local AD LDS database on that Edge Server. But if any of these subscribed objects where created on Exchange 2013 after it was installed, then they will have an ExchangeVersion equal to 0.20 (15.0.0.0). The Exchange 2010 SP3 Remove-EdgeSubscription cannot process this object and so fails with:

Remove-EdgeSubscription : Can’t make this change because the object’s ExchangeVersion property is 0.20 (15.0.0.0), which is not supported by the current version 0.1 (8.0.535.0). You will need a newer version of Exchange to make this change. Property Name: ExchangeVersion
At line:1 char:24
+ Remove-EdgeSubscription <<<<  edge2 -Verbose
+ CategoryInfo          : NotSpecified: (0:Int32) [Remove-EdgeSubscription], DataValidationException
+ FullyQualifiedErrorId : D8A49A14,Microsoft.Exchange.Management.SystemConfigurationTasks.RemoveEdgeSubscription

The way to fix this is to find and manually remove the object with an ExchangeVersion of 0.20 (15.0.0.0) from the AD LDS database and then repeat the Remove-EdgeSubscription cmdlet – as that should now work (unless you have two or more objects with the higher version number to locate and delete).

1. To find objects with an ExchangeVersion greater than “0.1 (8.0.535.0)”, which is the version Exchange 2010 will process, open ADSIEdit on the Edge server.
2. Right-click the ADSI Edit node at the top of the window and choose Connect to…
3. In the Connection Settings dialog (shown above), change the Select a well known Naming Context to Configuration and type the local server name and the AD LDS port in the Select or type a domain or server field. The server:port value should be EDGESERVERNAME:50389
   
4. Expand the tree view until you reach CN=First Organization,CN=Microsoft Exchange,CN=Services,CN=Configuration,CN={AD258B4D-CCB4-4125-80C1-7B73CE066341}
5. You now need to look at each object, starting with those you remember having created since 2013 was installed, for an object who’s msExchVersion value is not 4535486012416. For example, if you had created an accepted domain due to Federation in Exchange 2013 this would be a new object since 2010. This object (under CN=Accepted Domains,CN=Transport Settings,…) has a value of 88218628259840.
6. To validate that this is the correct object to manually delete, from the Exchange Management Shell on the Edge server, enter Get-Object | FT name,ExchangeVersion where Object is the cmdlet that you are looking to query – in my case it would be Get-AcceptedDomain.
7. This object has a newer ExchangeVersion and so it is (at least) this object that is stopping Exchange EdgeSync from being removed.
8. Manually delete the object in ADSI Edit (it is safe to do this as it will resync from the Exchange organization if you recreate Edge Subscription later). Do not delete it from the Active Directory with ADSI Edit – just from AD LDS. Take care to only delete this object and not the parent object.
9. Once this object is gone, try Remove-EdgeSubscription servername again. If this is the only object, then the Edge Subscription will be removed in the Edge Server

You can now carry on with whatever it was that you were doing that required a removal of the Edge Subscription.