Find-CertificateAuthority does not work in a multi-domain forest

[Raimund Andrée [MSFT]]

Find-CertificateAuthority looks for the configuration partition using the domain name instead of the forest name.

$cdpContainer = [ADSI]"LDAP://CN=CDP,CN=Public Key Services,CN=Services,CN=Configuration,$DomainName"

Using the RootDSE object should solve that.