A Global Catalog Server could not be located - All GC's are down

**manishdk** · 12-04-2008

If I am trying to add a new user into our active directory then I am getting this error "windows cannot verify that the user name is unique because the following error occured while trying to contact the global catalog server: The server is not operational." If I am checking in the ntds settings properties there is a tick on the global catalog. After I do a dcdiag, then I am getting the below errors:

Domain Controller Diagnosis

Performing initial setup:
* Verifying that the local machine nwscdc2, is a DC.
* Connecting to directory service on server nwscdc2.
* Collecting site info.
* Identifying all servers.
* Identifying all NC cross-refs.
* Found 2 DC(s). Testing 2 of them.
Done gathering initial info.

Doing initial required tests

Testing server: Default-First-Site-Name\NWSCDC
Starting test: Connectivity
* Active Directory LDAP Services Check
* Active Directory RPC Services Check
The clock difference between the home server NWSCDC2 and target
server

NWSCDC is greater than one minute. This may cause Kerberos authentication failures. Please check that the time service is working properly. You may need to resynchonize the time between these servers.

......................... NWSCDC passed test Connectivity

Testing server: Default-First-Site-Name\NWSCDC2
Starting test: Connectivity
* Active Directory LDAP Services Check
* Active Directory RPC Services Check
......................... NWSCDC2 passed test Connectivity

Doing primary tests

Testing server: Default-First-Site-Name\NWSCDC
Starting test: Replications
* Replications Check
* Replication Latency Check
DC=ForestDnsZones,DC=nwsc,DC=co,DC=ug
Latency information for 4 entries in the vector were ignored.
4 were retired Invocations. 0 were either: read-only
replicas and are not verifiably latent, or dc's no longer replicating this
nc. 0 had no latency information (Win2K DC).
DC=DomainDnsZones,DC=nwsc,DC=co,DC=ug
Latency information for 4 entries in the vector were ignored.
4 were retired Invocations. 0 were either: read-only
replicas and are not verifiably latent, or dc's no longer replicating this
nc. 0 had no latency information (Win2K DC).
CN=Schema,CN=Configuration,DC=nwsc,DC=co,DC=ug
Latency information for 9 entries in the vector were ignored.
9 were retired Invocations. 0 were either: read-only
replicas and are not verifiably latent, or dc's no longer replicating this
nc. 0 had no latency information (Win2K DC).
CN=Configuration,DC=nwsc,DC=co,DC=ug
Latency information for 9 entries in the vector were ignored.
9 were retired Invocations. 0 were either: read-only
replicas and are not verifiably latent, or dc's no longer replicating this
nc. 0 had no latency information (Win2K DC).
DC=nwsc,DC=co,DC=ug
Latency information for 8 entries in the vector were ignored.
8 were retired Invocations. 0 were either: read-only
replicas and are not verifiably latent, or dc's no longer replicating this
nc. 0 had no latency information (Win2K DC).

Can anyone please help

**Big Fish** · 12-04-2008

Could you please post the ipconfig /all from all the DC and DNS servers. Have you checked if a firewall is running on the DCs or not? Have you tried to change anything before this happened? Or the issue comes after addming a new DC or so? Let us also know how many sites do you have with you?

**HELLIAN** · 13-04-2008

Can you check that your DCs have in total the 5 FSMO roles. Since you are talking about an old crashed DCs, are there any entries in AD or DNS from that machine? Thanks.