Which command line tool is used to create trust?

Create Forest Trust Using PowerShell http://social.technet.microsoft.com/wiki/contents/articles/11911.how-to-create-forest-trust-using-powershell.aspx

Open Command Prompt.
Type: netdom trustTrustingDomainName/d:TrustedDomainName/add   ValueDescription TrustingDomainName Specifies the DNS name (or NetBIOS name) of the trusting domain in the trust being created.
TrustedDomainName Specifies the DNS name (or NetBIOS name) of the domain that will be trusted in the trust being created.
Notes To perform this procedure, you must be a member of the Domain Admins group or the Enterprise Admins group in Active Directory, or you must have been delegated the appropriate authority.
As a security best practice, consider using Run as to perform this procedure.
For more information, see Default local groups, Default groups, and Using Run as.
To open a command prompt, click Start, point to All programs, point to Accessories, and then click Command prompt.
This command-line method requires the Netdom Windows support tool.
For information about installing Windows support tools, see Related Topics.
Other switches can be used to assign a password or determine the direction of the trust.
For example, to make a two-way, transitive trust, you can use the following syntax: netdom trustTrustingDomainName/d:TrustedDomainName/add/twoway To view the complete syntax for this command, at a command prompt, type:netdom trust | more