Hi,
Below is only correct when we are dealing with domains within the same
forest.
GPOs that are linked to Active Directory site objects affect all
computers in the site. Therefore, any Group Policy object that is
linked to a site is applied to all computers in that site, without
regard to which domain (in the forest) contains the computers.
This means that computers in multiple domains within a forest can
potentially receive the same Group Policy object when you use
site-linked GPOs. It also means that a given client computer could
receive GPOs from multiple domains in the forest. Note that the GPO
exists as a stored entity only in a single domain and it must be read
from that domain when the affected clients read their site-linked Group
Policy.
If multiple domains are set up across wide area network (WAN)
boundaries, the site configuration should take this into account. If it
does not, the computers in another domain access a site-linked GPO
across a WAN link. This increases the processing time for Group Policy.
In general, it is recommended that you link GPOs to domains and
organizational units rather than sites.
http://technet2.microsoft.com/Windo...9f85-4bee-84c9-1994921658cd1033.mspx?mfr=true
Harj Singh
Power Your Active Directory Investment
www.specopssoft.com