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Lesson Learned #465:Unraveling DNS Errors in "myserver.database.windows.net": Nonauthoritative host

Jose_Manuel_Jurado's avatar
Jan 03, 2024

Today, I got a service request with the following error message: .Net SqlClient Data Provider,SqlErrorNumber=11002,Class=20,ErrorCode=-2146232060,State=0,Errors=[{Class=20,Number=11002,State=0,Message=A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - This is usually a temporary error during hostname resolution and means that the local server did not receive a response from an authoritative server.),},],''Type=System.ComponentModel.Win32Exception,Message=This is usually a temporary error during hostname resolution and means that the local server did not receive a response from an authoritative server,Source=,'

 

Following I would like to share my lessons learned here. 

 

In the realm of DNS, comprehending errors like "Nonauthoritative host not found" (Error code 11002) and "WSAHOST_NOT_FOUND" error 11001, is essential, especially when dealing with specific domains like "myserver.database.windows.net".

 

Nonauthoritative host not found: This error suggests that while the DNS server queried can access some data about the domain, it lacks authoritative details from the primary DNS server of "database.windows.net". This issue might stem from temporary connectivity problems with the authoritative DNS server. It is important to discuss with your networking team to review the DNS configuration of your server.

 

If I compared with the error WSAHOST_NOT_FOUND (11001): This error is more definitive, indicating that the DNS server does not recognize "myserver.database.windows.net". It implies that the host name is either unregistered or nonexistent in the DNS database.

 

Resolving the Issues:

 

  1. Host Name Verification: Ensure "myserver" is correctly configured and registered.
  2. DNS Settings: Check if the correct DNS server is in use, especially if relying on internal DNS.
  3. Public DNS Testing: Temporarily switch to a public DNS or Azure DNS. 
  4. Network Connectivity: Investigate any network issues affecting DNS resolution.
  5. Diagnostic Tools: Employ tools like nslookup or dig for troubleshooting.
  6. Service Provider Consultation: If unresolved, contact the service provider of "database.windows.net" for assistance.

 

For detailed Winsock error codes, refer to Microsoft's documentation here.

 

Enjoy!

Published Jan 03, 2024
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