Unable to reach or network mirror does not exist - server network address

Question

I read a series of articles on how to configure mirroring on SQL Server 2012. I went through all the steps and everything worked until the last step arrived, which did not work.

When I run this on Principal:

ALTER DATABASE MyDBName SET PARTNER = 'TCP: //1.2.3.4: 5022';

I get this error:

The server network address "TCP: //1.2.3.4: 5022" cannot be reached or does not exist.

When I run the ALTER statement shown above, but in the mirror it works fine.

I tried all the steps in this article.

Important points:

• Primary and Mirror servers are located in different data centers, and not on the same network. VPN is not connected. Do not completely trust each other.
• I can connect to the mirror via SSMS in Primary and run queries. And vice versa.
• I configured certificates on each server to establish trust relationships. Everything worked during setup and configuration, no errors.
• I configured the endpoints on both servers and confirmed that they are active / enabled.
• I opened port 5022 on both servers by configuring the firewall rules for inbound and outbound windows. I can use telnet for Mirror from Principal, and vice versa - the ports look open, no problem.
• In the troubleshooting guide mentioned above, I tried to follow steps 1-6. I have not tried 7, removing the endpoints and recreating them because they look completely valid and active to me.

Looking for some ideas on this.

Answer 1

If you can connect this port to the host computer, everything will be alright with the TCP / IP settings and the firewall.

I remember that I had a similar problem in the past. Unfortunately, I don’t remember the exact solution, but it was related to the security / authentication of the endpoints and the SQL Server service account that does not have sufficient permission on the mirrored machine. Unfortunately, in this case the error message is quite misleading. Script endpoints and check their settings, SSMS does not have this interface. Another thing you can check is that you have the option to also connect to port 5022 from the mirror to the host machine. You will get the same error message if the connection is not possible from both instances.

Sorry I cannot provide you with the right solution, but perhaps this indicates the right direction.

Answer 2

Unfortunately, in MS SQL there are rather uninformative error messages. The problem may be an authorization problem, and the server will still say that "the network address cannot be reached."

Given that "servers are in different data centers", how is authentication performed? The MSSQL service (on server1) must be running as a valid db user (on server2 and vice versa) to do the mirroring job.

Answer 3

There may be several reasons.

In your SQL Server Management Studio, if you see a white bubble next to the server instance name, instead of a green bubble, you can try the following:

• “Allow the application through the firewall” and add “Windows Management Instrumentation (WMI)” for Windows Server 2012. If it is Windows Server 2008, you can enable “Remote Administration” through the firewall.

Answer 4

Is this supposed to be a colon?

ALTER DATABASE MyDBName SET PARTNER = 'TCP://1.2.3.4;5022' 

The half-colonometer is used when connecting to the IP / port when using the management studio.