[Microsoft][ODBC Driver 18 for SQL Server]TCP Provider: Error code 0x2749

[phelipelui]

Hello guys, I need some help with the problem bellow.
I tried to connect on sqlserver using this connect_string:

But received this error:
$ python3
Python 3.12.3 (main, Jun 18 2025, 17:59:45) [GCC 13.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.

import mssql_python

Establish a connection

Specify connection string

connection_string = "SERVER=localhost,1433;DATABASE=master;UID=sa;PWD=Passw0rd;Encrypt=yes;"
connection = mssql_python.connect(connection_string)
Traceback (most recent call last):
File "", line 1, in
File "/home/lpbispo/.local/lib/python3.12/site-packages/mssql_python/db_connection.py", line 36, in connect
conn = Connection(connection_str, autocommit=autocommit, attrs_before=attrs_before, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/lpbispo/.local/lib/python3.12/site-packages/mssql_python/connection.py", line 80, in init
self._conn = ddbc_bindings.Connection(self.connection_str, self._pooling, self._attrs_before)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: [Microsoft][ODBC Driver 18 for SQL Server]TCP Provider: Error code 0x2749

---> mssql-python==0.8.1
---> WSL ubuntu
---> sqlserver running and accepting connections by management studio

I did not find any example where the database port is explicit on connect string.
I looked here:

• Connection · microsoft/mssql-python Wiki;
• mssql-python/tests/test_003_connection.py at main · microsoft/mssql-python;
• mssql-python/mssql_python/connection.py at main · microsoft/mssql-python.

I am repoting this because some databases may not be on default port
"By default, MS SQL Server listens on port 1433 for TCP/IP connections. However, this can be changed for various reasons, including security considerations or to accommodate multiple instances of SQL Server on the same machine." https://aextestusw.autodesk.com/default-port-mssql

[dlevy-msft-sql]

Hi @phelipelui - Thanks for pointing that out! I've updated the connection page to include more detail.

Are you able to connect now or still having issues? I see you used a port number in your connection string above and still failed to connect. Since you're running in WSL, I'd suggest trying the actual host name instead of localhost to see if that works any better.

Please let us know!

Thanks,

Dave

[phelipelui]

Connecting directly from windows powershell works.
After enable TCP/IP, the connection worked from WSL too

Thank you for the attention.