Exchange is very dependent upon Active Directory domain controllers. The list of domain controllers currently being used by a server is usually one of the first pieces of information you should gather when you encounter an Exchange issue. While this can be done through the GUI, it is much easier to get the data through a script.
The first domain controller promoted into a forest is by default also made a global catalog server. If you want additional servers to contain the global catalog, you have to enable it. The global catalog on a domain controller becomes enabled when the low-order bit on the options attribute on the ntdSDSA object under the server object for the domain controller is set to 1. The DN of this object for dc1 in the Default-First-Site-Name site looks like this: cn=NTDSSettings,cn=DC1,cn=Default-First-Site-Name,cn=Sites,cn=Configuration, dc=rallencorp,dc=com.