- Enable the GC on the new server (open the Microsoft Management Console--MMC--Active Directory Sites and Services snap-in, navigate to Sites, select the name of the site that will contain the new GC server, navigate to Servers, select and expand the name of the new GC server, right-click NTDS Settings in the left-hand pane, select Properties, then select the Global Catalog check box).
- Wait until event ID 1119 appears in the new GC Directory Services event log.
- Disable the GC on the old server (in the Active Directory Sites and Services snap-in, navigate to Sites, select the name of the site containing the old GC server, select and expand the name of the old GC server, right-click NTDS Settings in the left-hand pane, select Properties, then clear the Global Catalog check box).
If you add or remove GCs and you use Exchange Server, you must reboot the Exchange servers to let them update the DSAccess topology report and begin using the new GCs--otherwise Exchange won't discover the GCs and use them for DSAccess. To create its AD topology view, DSAccess
- calls the Directory Service (DS) Locator service
- retrieves a list of all DCs and GCs from the local AD site
- contacts each server in the list
- caches as many as 10 active DCs and 10 active GCs
- reorders the active-GC list so that domain-local GCs are at the top of the list
- uses the cached DC and GC server list on a simple round-robin basis for global information lookups.