Question 1:
In a multi-domain forest, there are six different types of trusts that include parent-child, tree-root, external, realm, forest and shortcut trusts. Each of these trusts is further classified into transitive and non-transitive types with either one-way or two-way directions. The communication between different domains occurs only through establishing one of the different types of trusts. The default trusts (parent-child and tree-root) are automatically created at the time of active directory installation ("How Domain and Forest Trusts Work: Domain and Forest Trusts", 2014).
Apart from the default trusts, one can choose to install other trusts through the new trust wizard. An external trust is non-transitive and is created for domains in a different forest. Real trust is beneficial and works between Kerberos V5 realm and active directory domain. The realm is both transitive and non-transitive. Forest trusts establish a trust relationship between the root domains of two different forests. Shortcut trust occurs in the same forest across different domains under the same domain tree ("How Domain and Forest Trusts Work: Domain and Forest Trusts", 2014).
Question 2:
RODC (Read-Only Domain Controllers) is the latest type of domain controller that came into existence since Windows Server 2008. RODC is beneficial for organizations to deploy domain controller where physical security is not assured. RODC provides enhanced security, fast logon and an efficient access to network resources. Inadequate security of physical devices is te primary reason that necessitates the deployment of RODC, other reasons include special administrative requirements of using this domain controller like controlling Line-of-Business (LOB) applications ("AD DS: Read-Only Domain Controllers", 2011).
There are two new features for RODC management that provide unique deployment benefits. The manageability features are Branch Office Server (BOS) and Branch Office application (BOA) administration. BOS allows delegation of administrative roles to non-administrative users for special conditions in a branch office. BOA allows RODC deployment for specific application administration in a branch office ("Advantages That An RODC Can Provide To An Existing Deployment", 2012).
References
AD DS: Read-Only Domain Controllers. (2011). Technet.microsoft.com.
Retrieved 20 May 2016, from https://technet.microsoft.com
/en-us/library/cc732801(v=ws.10).aspx
Advantages That An RODC Can Provide To An Existing Deployment. (2012).
Technet.Microsoft.Com. Retrieved 20 May 2016, from https://technet.microsoft.com
/en-us/library/cc770320(v=ws.10).aspx.
How Domain and Forest Trusts Work: Domain and Forest Trusts. (2014).
Technet.microsoft.com. Retrieved 20 May 2016, from https://technet.microsoft.com
/en-us/library/cc773178(v=ws.10).aspx.
