How can I find out which is my GC?

The easiest way is simply to follow the procedure you would follow to promote a GC, as per http://support.microsoft.com/kb/296882. In step 5, if the checkbox marked Global Catalog is ticked, that server is a Global Catalog. You then simply repeat and lookup the value for the other server.

Alternatively, there is a batch file method using Netdom and Repadmin, see http://windowsitpro.com/article/articleid/92811/how-can-i-use-the-support-tools-to-list-the-global-catalog-servers-in-my-domain.html, or you can run a simple DNS query. At a command prompt, simply type
nslookup gc._msdcs.%USERDNSDOMAIN%

-tigermatt

Hello,

You can do this from the command line or from the Active Directory Sites & Services (ADSS) utility.  

ADSS:  Expand the 'Sites' container, then the 'Site name' container, then 'Servers'.  The servers container contains all of the domain controllers for that site.  Select each server and go to the properties of the 'NTDS Settings' applet.  The option of whether or not each DC is a global catalog can be determined from there.  There may be more than one GC per site, but there has to be one.  

As a default, the GC is created on the first DC installed into an active directory site.

Thanks guys for the quick reply. Also, if I wanted to change the GC server would it be as simple as unchecking the box and checking the box of the desired server?

Thanks

Also, DNS will have to update SRV records to reflect the change.  I would not do this during peak business hours.

/F

Another reason for keeping one server as a GC while the other builds :-)

thanks guys.