SQL Server 2012 turns on TCP/IP logon and enables the default 1433 port

Client applications can connect to Microsoft SQL Server by using TCP/IP, Named pipes, VIA, or the shared memory protocol. You can implement these protocols by using the client network libraries that are contained in the SQL Server Native clients DLL. To configure the SQL Server client, use SQL Server Configuration Manager, which is the new Microsoft Management Console (MMC) snap-in that you can find from the Start menu or from the Computer Management utility. SQL Server Configuration Manager provides information about the Client network protocol and allows you to configure certain protocol options. You can also use SQL server Configuration Manager to change the default network protocol and define the methods that connect to a specific server.

To start SQL Server Configuration Manager, click Start, point to Program files, points to Microsoft SQL Server and configure tools, and then click SQL Server Configuration Manager. To access the Client configuration section, click SQL Server Native Client Configuration in the console pane.

Change the order in which clients try to use all enabled protocols when they connect to the server:

Protocols available for early SQL Server clients include TCP/IP, Named Pipes, VIA, and Shared Memory.

Using the VIA protocol is not recommended. Subsequent versions of Microsoft SQL Server will remove the feature (the VIA protocol has been removed in SQL Server 2012)

The Shared Memory protocol can only be used to communicate with processes running on the same computer as SQL Server. It is enabled by default. Windows manages the security of Shared Memory. In all Microsoft client network protocols, this is the safest: Different processes can read the same piece of data in physical memory, which is one of the most efficient ways to exchange data. When the shared Memory protocol is enabled, SQL Server always tries to use the protocol first.

Right-click the TCP/IP protocol to see detailed property information for the protocol. For example, the default port is 1433. In fast local area network (LAN) environments, and named pipe clients are comparable in performance. The TCP/IP sockets also support the backlog queue. When you try to connect to SQL Server, the queue can have a limited amount of smoothness compared to Named Pipes, which can cause pipeline busy errors. TCP/IP works better in slow LAN, WAN, or dial-Up Networking. When network speed is not a problem, Named Pipes is a better choice because it is more powerful, easier to use and has more configuration options. If the server shuts down the TCP/IP protocol and only enables named pipes, some security risks can be avoided.

Named Pipes is a named pipe, a protocol developed for a local area network that is used by a process to pass information to another process, so that the output of one process is the input of another process. It shields the underlying network protocol details, so you can use named pipes to communicate between processes without knowing the network protocol. The process of creating a pipeline is called a pipe server, and a process connected to a pipeline is called a pipe client. All instances of a named pipe share the same pipe name, but each instance has a separate cache and handle and provides a separate pipeline for customer-service communication, which ensures that multiple pipeline customers can use the same named pipe at the same time.

References: http://www.cnblogs.com/reveyjay/archive/2012/02/12/2348015.html

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SQL Server does not support VIA, Banyan Vines Sequential Package Protocol (SPP), Multiprotocol, AppleTalk, or NWLink ipx/spx network protocols. Clients that previously connected using these protocols must choose a different protocol to connect to SQL Server. You cannot use SQL Server Configuration Manager to configure a WinSock proxy. To configure the WinSock proxy, see your ISA Server documentation.

Let's look at the connection options for SQL:

If you do not modify it, the default configuration is used.

After clicking on the option, in the connection properties, we can modify the client network protocol used.

The default priority order is shared memory, TCP/IP, Named pipes, respectively.

By default, when the SQL Server 2012 installation is complete, the above three protocols are enabled.

By default, on SQL native, you can connect directly using shared memory and TCP/IP, but if you use Named pipes, you need some configuration.

This time you need to check the server remote settings are correct, specific reference blog:http://blog.csdn.net/xiadingling/article/details/8215282

Another point is: By default, the instance-level Named pipes protocol is not enabled, so be sure to enable it manually.

After you finish the configuration above, don't forget to restart the SQL Server server to take effect.

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You can use the following SQL statement to query the currently used connection mode.

SQL Server 2012 turns on TCP/IP logon and enables the default 1433 port