A network interface layer that Microsoft SQL Server uses to communicate with database client software.
Net-Libraries are specific to each type of interprocess communication (IPC) mechanism. A Net-Library can be loaded for each IPC mechanism being used - for example, one Net-Library for named pipes communication and another for TCP/IP sockets. Net-Libraries are used at both the server and client levels. This allows clients on different networks to be supported simultaneously using the built-in Microsoft Windows NT and Windows 2000 support for running multiple network protocols simultaneously on one system.
Net-Libraries on SQL Server listen for incoming connection attempts from database clients. SQL Server has a multiprotocol networking library that listens using named pipes, TCP/IP ports, and Sequenced Packet Exchange (SPX) sockets.
Be sure to distinguish between the particular IPC mechanism and its underlying network protocol. Some IPC mechanisms (such as named pipes) can function simultaneously over multiple network protocols such as NetBEUI, NWLink IPX/SPX, and TCP/IP.