We have an AD with 8 sites. The main DC's are in our head office. Located on the other sites we have 7 more DC's. The domain is Windows 2003 Native AD. Under Active Directory Sites and Services I noticed that some connections are automatically generated, but most of them are not and were created manually.
The sites are connected through 2Mbit SDSL connections which are up 24/7. Most site to site connections are now set to one or two DC's at the main office replicating over IP twice per hour. DC's at the head office are connected to the other DC's at the head office by RPC connections four times per hour.
My questions is how many NTDS connection should any DC on a site have. Should it only be connected to one DC at the main office? All DC's at the main office or should it be connected to every possible DC on every possible site (making it mandatory to create lots of NTDS connection objects by hand).