I'm having an issue with a PowerShell script I am writing to automate Domain Controller promotions in AD.
I get the following error when run:
Install-ADDSDomainController : Object reference not set to an instance of an object.
+ Install-ADDSDomainController -InstallDns -DomainName "$localdomain" - ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Install-ADDSDomainController], NullReferenceException
+ FullyQualifiedErrorId : System.NullReferenceException,Microsoft.DirectoryServices.Deployment.PowerShell.Commands.InstallADDSDomainControllerCommand
This is the PowerShell script I wrote:
$Network = Get-WmiObject -Class Win32_NetworkAdapterConfiguration -Filter IPEnabled=TRUE
$defaultgateway = ($Network.DefaultIPGateway -like "*.*.*.*")
$localsitedc = switch ($defaultgateway)
{
"192.168.40.1" {"DC0.east.contestco.local"}
"192.168.41.1" {"DC0.west.contestco.local"}
"192.168.42.1" {"DC0.north.contestco.local"}
"192.168.43.1" {"DC0.south.contestco.local"}
"192.168.48.1" {"DC0.mobile.contestco.local"}
}
$localdomain = "{1}" -f ($localsitedc.Split(".",2))
$seclocalpasswd = ConvertTo-SecureString "MySecretLocalPassword" -AsPlainText -Force
$secadmpasswd = ConvertTo-SecureString "MySecretADPassword" -AsPlainText -Force
$mycreds = New-Object System.Management.Automation.PSCredential ("CONTESTCO\Administrator", $secadmpasswd)
Install-ADDSDomainController -InstallDns -DomainName $localdomain -ReplicationSourceDC $localsitedc -SafeModeAdministratorPassword $seclocalpasswd -Credential $mycreds
Any help would be appreciated.
Thanks
2 Answers 2
Please check that
The machine you are installing as a DC has the has a gateway set and DNS Server points to a working DC/DNS server as listed in the post.
The machine you are installing as a DC has the necessary ports open to other sites as well (AD, LDAP, DNS ports), in the initial communication it may have to communicate with DNS servers for forest-wide queries. You may verify this with netstat -bn on the machine and check for a Sync_Sent status of an outgoing connection. You may refer to https://learn.microsoft.com/en-us/troubleshoot/windows-server/active-directory/config-firewall-for-ad-domains-and-trusts.
From the post, I understand that there are regional Active Directory domains in a single AD Forest. Pls ensure that AD replication between sites/domains are successful and also FSMO roles are in place and active. For the AD replication check repadmin /replsummary may be used. For the FSMO roles netdom query fsmo command may be used. Every domain should have three FSMO roles of its own domain + should be able to communicate with the two FSMO roles for the forest which are located in the root domain of the forest.
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I found that "-Force" was needed at the end of the Install-ADDSDomainController command. I forgot this command asked questions that the user needed to answer.
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