Use PowerShell to set Domain Controller DNS Forwarders to use Cisco Umbrella/OpenDNS

Set-UmbrellaDNSForwarders.ps1

#Set the public IPs for Cisco Umbrella / OpenDNS
$openDNS = "208.67.220.220", "208.67.220.222", "208.67.222.220", "208.67.222.222"

#Get a list of your Domain Controller.
$dcs = Get-ADcomputer -SearchBase "OU=Domain Controllers,DC=your,DC=domain,DC=com"
#you can also simply use Get-ADDomainController -filter *

#Iterate through each DC
foreach($DC in $dcs){
    #Log the current DNSForwarder settings
    $currentForwarder = Get-DnsServerForwarder -ComputerName $dc.name
    $dc.name | out-file C:\path\to\log\previousForwarders.txt -Append
    $currentForwarder | out-file C:\path\to\log\previousForwarders.txt -Append

    #Set the desired DNS Forwarder IP addresses and ensure UseRootHint is set to false per Cisco documentation 
    # https://support.umbrella.com/hc/en-us/articles/4404435963412-Umbrella-as-a-DNS-forwarder-in-Windows-Server
    Set-DnsServerForwarder -ComputerName $DC.name -IPAddress $openDNS -UseRootHint $false -Verbose

}