I'm in the process of planning for an NT to Active Directory migration for an environment that is approx. 3000 users, 3000 workstations, and 350 servers. I'm working on planning my DNS infrastructure at the moment. Initially we are planning on having 4 domain controllers that will also serve as our AD-integrated DNS servers in the DHCP scope. We will remove the root-hints from these four machines and set them up to forward to a pair of caching DNS servers that will then forward out to our ISP's servers. My question is, when a client machine or member server starts up and registers itself in DNS, will it always try to register with the first DNS server in it's TCP/IP properties/DHCP assignment, or does it pick one of its DNS servers at random? I'm concerned because if this is the case, then that one DNS server/Domain Controller that is first in the DHCP scope will be getting slammed first thing in the morning with all of the authentication requests and DNS registrations that it will be receiving. Any suggestions are appreciated. Thanks in advance.