Fix SQL server error 233 in Microsoft

Microsoft SQL 233 error arises as a result of firewall restrictions or when the limit of a session connection is duly exceeded.

We have seen a rising Support request from our Customers regarding solving this problem and other SQL related issues as part of our Linux Support Services.

In this Context we shall see the various causes of the SQL server error and how best to fix it.


Common reasons why SQL server error 233 triggers

SQL users tends not to be able to access their Database even when they try to get in with the correct credentials. This could lead to frustration but you will get a solution here. Below are the factors that causes this error;


i. When the TCP/IP protocol is not active.

ii. When Shared Memory Protocol is not active.

iii. When the Names Pipes Protocol is not active.

iv. When Mixed mode is not assigned in the SQL server.

v. When the Virtual Interface Adapter is not active.

vi. Windows Firewall restricting the View Port.

vii. When there is an interruption in the Remote Connection.

viii.When the allowed amount of connections is exceeded.


We shall look into Some of these factors and how to resolve.


Mixed mode not assigned in the SQL server.

Mixed Mode also referred to as SQL Authentication mode helps in allocating an alternative Login opportunity in the System Administration account. Due to this provision, a separate username and password can be used to access the SQL server in conjunction with the one available in Windows. Therefore, if this feature is not active, the 233 error can be triggered. You can troubleshoot by trying to access SQL Server Management Studio (SSMS) the system by following the steps below to get a solution;


1. Use the Windows Authentication to log into SSMS.

2. Click on the server and right click to access the properties.

3. Select the Security option on in the Properties window.

4. Modify the Server Authentication setting and change from Windows Authentication to SQL Server and Windows Authentication mode.

5. Perform a restart of the SQL server to complete the process.


When TCP/IP protocol is inactive

TCP/IP needs to be functioning properly and active for SQL Server to Work without issues. To activate it, follow the steps below;


1. From the MS SQL Server Main Window, Navigate to the configuration tools section.

2. You will see the SQL Server configuration manager and then open SQL Server Network Configuration in the system.

3. Activate the TCP/IP from the window and restart the SQL Server to enable the changes to take effect.


Shared Memory Protocol not active

Clients utilize the SQL Server Shared Memory protocol to access the SQL Server instance running on the same machine as the server. Most users have experienced issues in logging into the SQL server. Authentication concerns like this is due the Shared Memory Protocol not active. To activate it, follow the steps below;


1. From the Start Menu, Click the All Programs and then Select MS SQL Server.

2. Next you will see the Configuration Tools where you should  click on SQL Server configuration Manager.

3. Then Select the SQL Server Network Configuration tab and make a right click on the Shared Memory option to complete the activation process.

After making the changes, restart the SQL server.


Need support in solving SQL Databases errors? You can use our Service.



In Summary, We have observed the common reason for Microsoft SQL server error 233  and we discussed about how to fix this Database issue. Our Linux Support Team offers Server Management Services.

Most Microsoft SQL Server users experience an error 233 when they are trying to login to their database.

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