You can add trusted domains to authenticate against in the Windows Integration pane of LDAP Servers dialog.
To add a trusted domain to the list, enter the domain name in the field at the bottom of the Windows Integration pane and click Add. To delete a domain from the list, select it in the list and click Delete.
To allow logins only for users in domains added to the trusted domains list, select Restrict Autologon to Windows User in Trusted Domains. To allow authentication to all available domains, deselect this option.