I have setup Failover Cluster Instance on 2 nodes with Windows Server 2008 and SQL Server 2012 running on a SAN storage with "Node and Disk based Quorum", DTC and public and Private IP communication.

Now I want to setup multi-subnet cluster by adding another two nodes and a SAN storage from different subnet.

I have following questions in mind for which I am looking for your expert help:-

1. Do we need to enable communication between public IP of site1 servers and public IP of site2 servers and how?
2. How our existing cluster in site1 can be stretched up-to site2 so that DC2 will also have Active-Passive architecture when failover to site2?
3. How the Quorum will work in Node and Disk Majority mode in site2?
4. How the Private IP communication will work when SQL Server 2012 Cluster failover to site2?
5. What are the components we will replicate from site1 to site2 using SAN replication? Will quorum will also get replicated or we should exclude quorum from replication?

I am new in multi-subnet cluster setup and looking for your urgent help for my setup.

Dear Experts,

Can I hear some update from you guys. Looking for your much needed help.