My existing setup is this :
2 Exchange 2010 SP1 servers with CAS, HUB, MBOX roles all in Site A with subnet of lets say 10.0.1.0.
Everything is working peachy keen, however I want to add a 3rd Exchange 2010 SP1 server in a different site and lets say the subnet is 10.0.2.0.
I understand I need to activate DAC to prevent split brain, no problem. However, the 'cluster' has an IP in the first site i.e. 10.0.1.1 , and if I try to add a server from Site B into that DAG it completes but warns that the server in Site B has no IP in the subnet of the cluster.
What does this affect ? Is this a problem for me ?