Enable or disable a server network protocol

Applies to: SQL Server - Windows only

All network protocols are installed during installation, by SQL Server Setup, but may or may not be enabled. This article describes how to enable or disable a server network protocol in SQL Server by using SQL Server Configuration Manager or PowerShell. The Database Engine must be stopped and restarted for the change to take effect.

Remarks

• During setup of SQL Server Express edition, a login is added for the BUILTIN\Users group. This login allows all authenticated users of the computer to access the instance of SQL Server Express as a member of the public role. The BUILTIN\Users login can be safely removed to restrict Database Engine access to computer users who have individual logins or are members of other Windows groups with logins.

• SQL Server and Microsoft data providers for SQL Server up to SQL Server 2014 (12.x) only support TLS 1.0 and SSL 3.0 by default. If you enforce a different protocol (such as TLS 1.1 or TLS 1.2) by making changes in the operating system SChannel layer, your connections to SQL Server might fail, unless you install the appropriate update to add support for TLS 1.1 and 1.2 to SQL Server. For more information, see KB 3135244. Starting from SQL Server 2016 (13.x), all release versions of SQL Server include TLS 1.2 support without further updates required.

Use SQL Server Configuration Manager

1. In SQL Server Configuration Manager, in the console pane, expand SQL Server Network Configuration.

2. In the console pane, select Protocols for <instance name>.

3. In the details pane, right-click the protocol you want to change, and then select Enable or Disable.

4. In the console pane, select SQL Server Services.

5. In the details pane, right-click SQL Server (<instance name>), and then select Restart, to stop and restart the SQL Server service.

Use SQL Server PowerShell

Enable a server network protocol with PowerShell

1. Using administrator permissions, open a command prompt.

2. Start Windows PowerShell from the taskbar or Start menu.

3. Import the SqlServer module by entering Import-Module SqlServer.

4. Execute the following statements to enable both the TCP and named pipes protocols. Replace <computer_name> with the name of the computer that is running SQL Server. If you are configuring a named instance (including SQL Server Express edition), replace MSSQLSERVER with the instance name.

   To disable protocols, set the IsEnabled properties to $false.

   You can run this script from any machine, with or withour SQL Server installed. Make sure you have the SqlServer module installed.

   #requires the SqlServer module
   Import-Module SQLServer
   
   $wmi = New-Object Microsoft.SqlServer.Management.Smo.Wmi.ManagedComputer <#computer_name#>
   
   # List the object properties, including the instance names.
   $Wmi
   
   # Enable the TCP protocol on the default instance.
   $uri = "ManagedComputer[@Name='<#computer_name#>']/ServerInstance[@Name='MSSQLSERVER']/ServerProtocol[@Name='Tcp']"
   $Tcp = $wmi.GetSmoObject($uri)
   $Tcp.IsEnabled = $true
   $Tcp.Alter()
   $Tcp
   
   # Enable the named pipes protocol for the default instance.
   $uri = "ManagedComputer[@Name='<#computer_name#>']/ServerInstance[@Name='MSSQLSERVER']/ServerProtocol[@Name='Np']"
   $Np = $wmi.GetSmoObject($uri)
   $Np.IsEnabled = $true
   $Np.Alter()
   $Np
   

Configure the protocols for the local computer

When the script is run locally and configures the local computer, SQL Server PowerShell can make the script more flexible by dynamically determining the local computer name. To retrieve the local computer name, replace the line setting the $uri variable with the following line.

$uri = "ManagedComputer[@Name='" + (get-item env:\computername).Value + "']/ServerInstance[@Name='MSSQLSERVER']/ServerProtocol[@Name='Tcp']"

Restart the Database Engine with SQL Server PowerShell

After you enable or disable protocols, you must stop and restart the Database Engine for the change to take effect. Execute the following statements to stop and start the default instance by using SQL Server PowerShell. To stop and start a named instance, replace 'MSSQLSERVER' with 'MSSQL$<instance_name>'.

# Get a reference to the ManagedComputer class.
CD SQLSERVER:\SQL\<computer_name>
$Wmi = (get-item .).ManagedComputer
# Get a reference to the default instance of the Database Engine.
$DfltInstance = $Wmi.Services['MSSQLSERVER']
# Display the state of the service.
$DfltInstance
# Stop the service.
$DfltInstance.Stop();
# Wait until the service has time to stop.
# Refresh the cache.
$DfltInstance.Refresh();
# Display the state of the service.
$DfltInstance
# Start the service again.
$DfltInstance.Start();
# Wait until the service has time to start.
# Refresh the cache and display the state of the service.
$DfltInstance.Refresh();
$DfltInstance

Related content

• Start, stop, pause, resume, and restart SQL Server services
• SQL Server Browser (SQL Server Configuration Manager)