In an environment in which two Smoothwalls are deployed, they are connected through an IPSec tunnel and all ports are open. One separate Windows domain are deployed behind each Smoothwall for a total of 2 Domains. A Domain trust has been established between the two domains and they say they are functioning fine, but users can't log into their AD accounts if they are behind the Smoothwall of the second Domain. Functioning level is Windows Server 2003 it says and these are Windows Server 2008 R2 Domain controllers. Does this trust need to be reestablished and functioning level raised?