Explanation/Reference:
Explanation:
In this scenario there are two forests.
Active Directory Forest Discovery can discover Active Directory sites and subnets, and then create Configuration Manager boundaries for each site and subnet from the forests that you have configured for discovery. When Active Directory Forest Discovery identifies a supernet that isassigned to an Active Directory site, Configuration Manager converts the supernet into an IP addressrange boundary.
Use client push installation to install the System Center 2012 Configuration Manager client software on computers that Configuration Manager discovered. You can configure client push installation for a site, and client installation will automatically run on the computers that are discovered within the site's configured boundaries when those boundaries are configured as a boundary group.
To configure the site to automatically use client push for discovered computers In the Configuration Manager console, click Administration.

In the Administration workspace, expand Site Configuration, and then click Sites.

In the Sites list, select the site for which you want to configure automatic site-wide client push

installation.
On the Home tab, in the Settings group, click Client Installation Settings, and then click Client Push

Installation.
(B) On the General tab of the Client Push Installation Properties dialog box, select Enable automatic

site-wide client push installation. Select the system types to which System Center 2012 Configuration Manager should push the client software by selecting Servers, Workstations, or Configuration Manager site system servers. The default selection is Servers andWorkstations.
Select whether you want automatic site-wideclient push installation to install the System Center 2012

Configuration Manager client software on domain controllers.
(A) On the Accounts tab, specify one or more accounts for System Center 2012 Configuration Manager

to use when connecting to the computer to install the client software. Click the Create icon, enter the User name and Password, confirm the password, and then click OK. You must specify at least one client push installation account, which must have local administrator rights on every computer on which you want to install the client. If you do not specify a client push installation account, System Center 2012 Configuration Manager tries to use the site system computer account, which will cause cross-domain client push to fail.