Two servers , same domain

Key Points to Consider:​

1. Active Directory Replication: Ensure that the second server (test2) properly replicated all necessary data from test1. This includes not just user accounts but DNS configurations, which are crucial for domain functionality.
2. DNS Configuration: When you turn off test1, if test2 is unable to resolve names or find the domain, it could be due to DNS issues. As a domain controller, test2 should have a DNS server role installed and configured correctly to point to itself as a DNS server. If test2 is set to use test1 as its DNS server, it won't be able to resolve names when test1 is offline.
3. IP Configuration: Check the IP configuration on test2. Make sure it has a static IP address and that its DNS settings are pointed to itself (or other available DNS servers, if applicable). This ensures it can resolve domain names even if test1 is unreachable.
4. Domain Controller Roles: Verify that test2 has taken on the necessary roles to be a functional domain controller. You can check this using tools like the Active Directory Users and Computers console or the Active Directory Sites and Services management console.
5. Network Connectivity: Confirm that there are no network issues preventing test2 from connecting to the Internet or other network resources while test1 is offline.

   Recommendations:​

   • Check the DNS Settings: On test2, ensure that the preferred DNS server is set to its own IP address.

• Force Replication: You can use the repadmin /syncall command to force replication from test1 to test2. Check for any replication errors.
• Review Event Logs: Look in the Event Viewer on both servers for any errors or warnings related to Active Directory and DNS that might give you more clues.
• Diagnostics Tools: Use tools like dcdiag to run a health check on both domain controllers. This will help identify any issues.

  Summary​

  You likely have a DNS misconfiguration or replication issue. Once you ensure that test2 can operate independently with proper DNS settings, you should see it handle requests even when test1 is turned off. Feel free to ask for further clarification or assistance!