For instance, you can connect to the default instance of SQL Server with TCP/IP if it is running on port 1433. If the SQL Server Browser service is not running, you are still able to connect to SQL Server if you provide the correct port number or named pipe. SQL Server Browser Service does not provide port resolution for default instances.įor information about starting and stopping the SQL Server Browser service, see Start, Stop, Pause, Resume, Restart the Database Engine, SQL Server Agent, or SQL Server Browser Service. The network library on the client application then completes the connection by sending a request to the server using the port or named pipe of the desired instance. SQL Server Browser responds with the TCP/IP port or named pipe of the requested instance. When SQL Server clients request SQL Server resources, the client network library sends a UDP message to the server using port 1434. SQL Server Browser support ipv6 and ipv4. When a server has two or more network cards, SQL Server Browser returns the first enabled port it encounters for SQL Server. SQL Server Browser reads the registry, identifies all instances of SQL Server on the computer, and notes the ports and named pipes that they use. Upon startup, SQL Server Browser starts and claims UDP port 1434. When connecting, clients can specify a specific port but if the port is dynamically assigned, the port number can change anytime SQL Server is restarted, so the correct port number is unknown to the client. If you want, a specific port can be assigned to an instance of SQL Server. By default, when enabled, both named instances and SQL Server Express are configured to use dynamic ports, that is, an available port is assigned when SQL Server starts. Because only one instance of SQL Server can use a port or pipe, different port numbers and pipe names are assigned for named instances, including SQL Server Express. During installation, TCP port 1433 and pipe \sql\query are assigned to the default instance, but those can be changed later by the server administrator using SQL Server Configuration Manager. This port, or "pipe," is used by that specific instance to exchange data with client applications. If the named pipes protocol is enabled, SQL Server listens on a specific named pipe. When an instance of SQL Server starts, if the TCP/IP protocol is enabled for SQL Server, the server is assigned a TCP/IP port. To resolve limitations of the SSRP system, SQL Server 2005 (9.x) introduced the SQL Server Browser service as a replacement for SSRP. This listener service responded to client requests with the names of the installed instances, and the ports or named pipes used by the instance. Only one instance of SQL Server can use a port, so when SQL Server 2000 (8.x) introduced support for multiple instances of SQL Server, SQL Server Resolution Protocol (SSRP) was developed to listen on UDP port 1434. SQL Server listened for incoming requests on port 1433, assigned to SQL Server by the official Internet Assigned Numbers Authority (IANA). Prior to SQL Server 2000 (8.x), only one instance of SQL Server could be installed on a computer. When installing a named instance of Analysis Services. When installing a named instance of the Database Engine including all instances of SQL Server Express. By default, the SQL Server Browser service starts automatically:
SQL Server Browser can be configured during setup or by using SQL Server Configuration Manager. SQL Server Browser is installed with SQL Server.
SQL Server Browser contributes to the following actions:Ĭonnecting to the correct server instanceĬonnecting to dedicated administrator connection (DAC) endpointsįor each instance of the Database Engine and SSAS, the SQL Server Browser service (sqlbrowser) provides the instance name and the version number. SQL Server Browser listens for incoming requests for Microsoft SQL Server resources and provides information about SQL Server instances installed on the computer. The SQL ServerBrowser program runs as a Windows service. Applies to: SQL Server (all supported versions)