http://serverfault.com/questions/486518/how-does-a-client-system-in-an-active-directory-network-find-in-which-site-it-re
Finding a Domain Controller in the Closest Site
http://technet.microsoft.com/en-us/library/cc978016.aspx
EX ARTICLES
原文：http://www.cnblogs.com/WCFGROUP/p/3514802.html
