Cannot connect with SSMS to SQL Server on Docker

Question

I have followed the official Microsoft documentation and I have installed SQL Server Docker image

As result I have a SQL Server image running on Docker at the IP address 172.17.0.2

I also can easily connect to it using sqlcmd with my dummy password

The problem is that I cannot connect to it through SSMS:

Login failed for user 'sa'. (Microsoft SQL Server, Error: 18456)

Of course I read other StackOverflow posts before posting this question and I have tried multiple logins:

• localhost,1433
• localhost:1433
• 172.17.0.2,1433
• etc...

How can I connect if localhost doesn't work as well as the IP address of the docker image?

Answer 1

In my case I've been running MSSQL Sever on my local machine + one on docker. Turning off mssql server service on host solved the issue.

[Edit]:

Adding technical reason as pointed by Francesco and it holds true in general for any ports:

That is not weird, if the port 1433 is taken by your host MSSQL, your MSSQL on docker cannot use the same port.