Regular readers of my blog will be aware of my friend who called me few days ago with very a funny SQL Problem SQL SERVER – SSMS Query Command(s) completed successfully without ANY Results. This time, it did not take long before he called me up with another interesting problem, although the issue he was facing this time was not that interesting and also very specific to him, however, he insisted me to share with all of you. Let us understand his situation at first.

My friend is preparing for DBA exam Exam 70-450: PRO: Designing, Optimizing and Maintaining a Database Server Infrastructure using Microsoft SQL Server 2008 and for the same, he was trying to set up replication on his local laptop. He had installed two different instances of SQL Server on his computer and every time when he started the mirroring, it failed with common error message.

The server network address “TCP://SQLServer:5023? cannot be reached or does not exist.
Check the network address name and that the ports for the local and remote endpoints are operational.
(Microsoft SQL Server, Error: 1418)

Well, before he contacted me, he searched online and checked my article written on the error in mirroring. However, he tried all the four suggestions, but it did not solve his problem. He called me at a reasonable time of late evening (unlike last time, which was midnight!). I even tried all the seven different suggestions myself, as previously proposed in my article; however, none of them worked. While looking at closely at services, I noticed something very simple. He was running all the instances on ‘Network Services’. In fact, his computer was a stand-alone computer. There was no network at all. Also, there was no domain or any other advance network concepts implemented.

I just changed services from ‘Network Services’ to ‘Local System’ as his SQL Server was running on his local system and there were no network services. This prompted to restart the services. As this was not the production server and his development machine, we restarted the services on the laptop (do not restart services on production server without proper planning).

After changing the ‘services log on’ account to localsystem, when he attempted to reconfigure the mirroring it worked right away. As usually in production server, proper domains are configured and advance network concepts are implemented I had never faced this type of problem earlier. My friend insisted to post this solution to his situation, wherein there was no domain configured and setting up mirroring was throwing an error. According to him, this is bound to help people, like him, who are preparing for certification using single system.

Reference: Pinal Dave (http://blog.SQLAuthority.com)