The following note has been added to several articles on TechNet. Previously we had some conflicting information regarding the utility Netdom and the creation of forest trusts.
Netdom cannot be used to create a forest trust between two AD DS forests. To create a cross forest trust between two AD DS forests, you can either use a scripting solution or the Active Directory Domains and Trusts snap-in.
Here is an example article of where the note has been added: Netdom trust