Connection Transport Protocols Transport Protocol Selection Transport Support for Local and Remote Connections --protocol  Value Transport Protocol Used Applicable Platforms TCP TCP/IP All SOCKET Unix socket file Unix and Unix-like systems PIPE Named pipe Windows MEMORY Shared memory Windows For a given connection, if the transport protocol is not specified explicitly, it is determined implicitly. For example, connections to  localhost  result in a socket file connection on Unix and Unix-like systems, and a TCP/IP connection to  127.0.0.1  otherwise. For additional information, see Section 4.2.4, “Connecting to the MySQL Server Using Command Options” . To specify the protocol explicitly, use the  --protocol  command option. The following table shows the permissible values for  --protocol  and indicates the applicable platforms for each value. The values are not case-sensitive. TCP/IP transport supports connections to local or remote MySQL servers. Socket-file, named-pipe, and shared-memory transports support connections only to local MySQL servers. (Named-pipe transport does allow for remote connections, but this capability is not implemented in MySQL.) If the transport protocol is not specified explicitly,  localhost  is interpreted as follows: If the transport protocol is specified explicitly,  localhost  is interpreted with respect to that protocol. For example, with  --protocol=TCP , a connection to  localhost  results in a TCP/IP connection to 127.0.0.1  on all platforms. TCP/IP and socket-file transports are subject to TLS/SSL encryption, using the options described in Command Options for Encrypted Connections. Named-pipe and shared-memory transports are not subject to TLS/SSL encryption. A connection is secure by default if made over a transport protocol that is secure by default. Otherwise, for protocols that are subject to TLS/SSL encryption, a connection may be made secure using encryption: Encryption and Security Characteristics Interpretation of localhost •On Unix and Unix-like systems, a connection to  localhost  results in a socket-file connection. •Otherwise, a connection to  localhost  results in a TCP/IP connection to  127.0.0.1 . •TCP/IP connections are not secure by default, but can be encrypted to make them secure. •Socket-file connections are secure by default. They can also be encrypted, but encrypting a socket-file connection makes it no more secure and increases CPU load. •Named-pipe connections are not secure by default, and are not subject to encryption to make them secure. However, the  named_pipe_full_access_group  system variable is available to control which MySQL users are permitted to use named-pipe connections. •Shared-memory connections are secure by default. 376