We've got two domain controllers. The second is a new one.
First DC ist Windows 2008 Standard, second Windows 2008 R2 Enterprise.
The Exchange Server is 2010 Standard Service Pack 2.
We need the second DC for failover if the first goes down. We tried this szenario (shut down the first domaincontroller) but Exchange is not work on.
We tried to Add the second DC as PreferredServer with the "Set-ADServerSettings" Command in the PowerShell.
[PS] C:\>Set-ADServerSettings -PreferredServer dc2.local
We get the following error message:
An Active Directory error 0x51 occured when trying to check the suitability of server dc2.local
'Active Directory response: The LDAP server is unavailable.
CategoryInfo: NotSpecified: (0:Int32) [Set-ADServerSettings], SuitabilityDirectoryException
FullyQulifiedErrorid: 96AD2D25, Microsoft.Exchange.Management.ADServerSettings.SetADServerSettings