EventLog: Server TCP provider failed to listen on [ 'any' <ipv6> 1433]. Tcp port is already in use

This isn't a duplicate; my scenario is different from others I've found:

MSSQLSERVER service does not start, port 1433 in use
https://blogs.msdn.microsoft.com/sql_pfe_blog/2016/10/05/tcp-port-is-already-in-use/
https://support.plesk.com/hc/en-us/articles/213409409

Differences:

• Neither cls & netstat -oanb -p tcp nor TCPView reveal anything listening on port 1433

• According to the EventLog message, this is occurring on IPV6

• The problem doesn't manifest for two named instances running on the same machine—only the default instance

To my knowledge, I'm not using IPV6 in any way, shape or form. I certainly haven't configured it.

The service will start when I make any of these configurations:

• Disable TCP/IP in SQL Configuration Manager

• Enable TCP/IP but turn off Listen All in TCP/IP Properties

• When Listen All is off, disable all IPs on the IP Addresses tab

If I do either of these, the service fails to start:

• Turn on Listen All

• Enable any IP address

This has got me pulling my hair out.

What's gone wrong here?

It might be over a year, but I do hope this will help others as well.

I could not confirm this, but it looks like the same SQL server instance like to assign the same port value to all the ports.

You'll need to open SQL Server Configuration Manager (If in case you cannot find it, https://blog.sqlauthority.com/2019/03/01/sql-server-sql-server-configuration-manager-missing-from-start-menu/)

Only assign one IP to use port 1433 and configure others for dynamic value, by setting TCP Dynamic Ports to 0 and blank off the TCP Port value. I chose 127.0.0.1 (loopback IP @ local) to bind with. Restart your SQL Server service.

StackExchange Database Administrators Q#230200, answer score: 9