I am in the process of adding a second domain controller to Windows server 2008 Enterprise.
On the first Domain controller I am running Exchange 2010.
The first domain controller is also a global catalog server.
Please see attached screen shot.
1. Why would I want to make this second domain controller, read only?
2. By default "Global Catalog server" is checked. Do I want to have this second domain controller be a GC server as well as the first? From what I understand, you can/should only have one GC server.
3. Should I also install a DNS server on this second DC? Is that a good idea in terms of redundancy or is it not necessary?