Question : Additonal Domain Controller

Dear Sir,

I recently installed additional domain controller in my network, I already have domain controller. I have few questions related to the installation

My domain controller is acting as DNS server, so when I installed additional domain controller, Active Directory along with DNS is replicated in additional domain controller from primary domain controller, fine.

My requirement is when the primary domain controller goes down I want my additional domain controller to become as DNS server and helps users to log in on the network.

Question 1: What DNS IP should I keep on Additional Domain Controller (the ISP DNS info (it will act as forwarder to the gateway) or the primary domain controller IP info.)

Question 2: Incase of primary domain controller failure, do I need any additional steps to make additional domain controller as primary or I dont need any steps

Question 3: do I need to seize or transfer FMOS roles to additional domain controller. If yes when should I perform this step as the primary domain controller will be in a failure state.

Question 4: How about Global Catalog, can I make additional domain controller global catalog along with primary domain controller which is already acting as global catalog

Answer : Additonal Domain Controller

These should sync automatically - give it a little time