A specific protocol must be enabled on both the client and the
server for the client to connect and communicate with the server.
SQL Server can listen for requests on all enabled protocols at once. The underlying operating system network protocols (such as TCP/IP) should already be installed on the client and the server. Network protocols are typically installed during Windows setup; they are not part of SQL Server setup. A SQL Server network library does not work unless its corresponding network protocol is installed on both the client and the server.
On the client computer, the SQL Native Client must be
installed and configured to use a network protocol enabled on the server; this
is usually done during Client Tools Connectivity setup. The SQL Native Client
is a standalone data access API used for both OLE DB and ODBC. If the SQL
Native Client is available, any network protocol can be configured for use with
a particular client connecting to SQL Server. You can use SQL Server Configuration
Manager to enable a single protocol or to enable multiple protocols and specify
an order in which they should be attempted. If the Shared Memory protocol
setting is enabled, that protocol is always tried first, it is available for
communication only when the client and the server are on the same machine.
The
following query returns the protocol used for the current connection, using the
DMV sys.dm_exec_connections:
SELECT
net_transport FROM sys.dm_exec_connections WHERE session_id = @@SPID;
http://www.mybasicknowledge.com/2012/09/sql-server-network-protocols-and.html
http://www.mybasicknowledge.com/2012/09/sql-server-network-protocols-and.html
