While doing SQL Mirroring, we receive the following as the most common error:
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)
The solution to the above problem is very simple and as follows.
Fix/WorkAround/Solution: Try all the suggestions one by one.
Suggestion 1: Make sure that on Mirror Server the database is restored with NO RECOVERY option (This is the most common problem).
Suggestion 2: Make sure that from Principal the latest LOG backup is restored to mirror server. (Attempt this one more time even though the full backup has been restored recently).
Suggestion 3: Check if you can telnet to your ports using command TELNET ServerName Ports like “telnet SQLServerName 5023”.
Suggestion 4: Make sure your firewall is turned off.
Suggestion 5: Verify that the endpoints are started on the partners by using the state or state_desc column the of the sys.database_mirroring_endpoints catalog view. You can start end point by executing an ALTER ENDPOINT statement.
Suggestion 6: Try the following command as one of the last options.
GRANT CONNECT ON ENDPOINT::Mirroring TO ALL
Suggestion 7: Delete the end points and recreate them.
If any of above solutions does not fix your problem, do leave comment here. Based on the comment, I will update this article with additional suggestions.
Please note that some of the above suggestions can be security threat to your system. Please use them responsibly and review your system with security expert in your company.
Reference: Pinal Dave (https://blog.sqlauthority.com), Many thanks to Solid Quality Mentors ) for their valuable suggestions.