Hello , I'm a student in Shahed university in IRAN . Now I'm become a member of our uni IT-Center . We are going to have an organized network with a en-bloc user authentication and proxy server. In comparison between MS AD and Samba , i want to choose Samba server ( cause of my belief in Open Source ) . Our plan have a Forest(root : shahed.ac.ir) and trees for faculties (like : eng.shahed.ac.ir , maybe have child ) and maybe for internet-site we may have a new forest (we should have trust between these domains ). In every site we should have DC and SQUID Proxy server ( for control and sharing internet in the best way ) . note : all of our clients have windows XP or se7en . My questions are : can we completely handle our plan with Samba server ? , for replication and trust what we should do ? we should use openLDAP for our plan ? what is your suggestion for what we are going to do ? witch distribution of LINUX is appropriate for our plan ? can we use it with share-point ? can we use it in .net programs ?