The SQL Server Network Interface (SNI) is the protocol layer that connects the client to the server via the network. It is made up of a set of APIs that are utilized by the database engine as well as the SQL Server Native Client (SNAC).
The following protocols are supported by SQL Server:
• Shared memory
• TCP/IP
• Named Pipes
• VIA — Virtual Interface Adapter
SQL Server supports several protocols:
• Shared memory: shared memory is the default protocol for connecting from a client running on the same machine as SQL Server. It is simple and fast. It can only be used locally, has no adjustable attributes, and is always tried first when joining from a local machine.
• TCP/IP: This is the most common SQL Server access protocol. It allows you to connect to SQL Server by entering an IP address and a port number. This usually happens automatically when you specify an instance to connect to. Your internal name resolution system converts the hostname portion of the instance name to an IP address, and you can connect to the default TCP port number 1433 for default instances, or the SQL Browser service will locate the appropriate port for a specified instance using UDP port 1434.
• Named Pipes: TCP/IP and Named Pipes are equivalent protocols in terms of the architectures in which they can be employed. Pipes was designed for local area networks (LANs), but it can be inefficient on slower networks, such as wide area networks (WANs).
• VIA: The Virtual Interface Adapter protocol offers high-performance communication between two systems. It necessitates specialized hardware on both sides and a dedicated connection.
