JSI Tip 5804. Starting Active Directory Users and Computers errors with 'The Server is not operational'?

You experience any of the following:

When you try to start Active Directory Users and Computers, you receive:

Naming Information cannot be located because:
The Server is not operational.
Contact your system administrator to verify that your domain is properly configured and is currently online.

When you try to start Active Directory Sites and Services, you receive:

Naming Information cannot be located because:
The server is not operational.
Contact your system administrator to verify that your domain is properly configured and is currently online.

When you try to start Active Directory Domains and Trusts, you receive:

The configuration information describing this enterprise is not available.
The server is not operational.

You may also experience a very slow logon process.

These problems are symptomatic of having TCP/IP port 389 closed. You may havemisconfigured TCP/IP Filtering.

Port 389 is used for LDAP (Lightweight Directory Access Protocol) connections. By default, TCP/IP Filtering is configured with the Permit All setting.

To verify your settings:

1. Right-click My Network Places on the domain controller which won't connect the Active Directory tool and press Properties.

2. Right-click the network connection that you use and press Properties.

3. Select Internet Protocol (TCP/IP), on the General tab, and press Properties.

4. Press the Advanced button.

5. Select the Options tab.

6. Select TCP/IP Filtering and press Properties.

7. Make sure that TCP Ports is configured for Permit All.

8. Press OK until the 'shutdown' message appears.

9. Shutdown and restart the domain controller.

See HOW TO: Configure TCP/IP Filtering in Windows 2000.