-a shows all connections and listening ports, while -b shows the executable components involved in creating each connection or listening port. In some cases, executable components are known, have multiple independent components, and in these cases, are included in the sequence of components that create connections or listening ports.

Be displayed.

In this case, the executable component name is at the bottom in [], the component it calls is at the top, and so on until the TCP/IP part. Pay attention to this option, it may take a long time, and it may fail if you don't have enough permissions.

TCP (Transmission Control Protocol) is a connection-oriented, reliable and byte-stream based transport layer communication protocol, which is defined by RFC 793 of IETF. In the simplified OSI model of computer network, it completes the functions specified by the fourth layer transport layer, and User Datagram Protocol (UDP) is another important transport protocol at the same layer.

In the Internet protocol group, the TCP layer is an intermediate layer above the IP layer and below the application layer. Reliable and pipe-like connections are often needed between application layers of different hosts, but the IP layer does not provide such a flow mechanism, but provides unreliable packet switching.