(1) The above is the mbuf and ifnet and ifaddr and le_softc and sockaddr_dl structures in Chapters 2 and 3 of the illustrations
(2) The following are the macros and functions of mbuf in Chapter 2 and the functions in Chapter 3
(3) The following is the macros and functions of the interface layer in Chapter 3
(4) 4 Chapter 4 1: Ethernet interface and three functions
(5) Chapter 4 2: Macros and functions of Ethernet interface
(6) Chapter 5 1: SLIP and loopback interface
(7) 7 Chapter 5 2: SLIP and loopback interface
(8) 8 Chapter 6 1 IP addressing and Chapter 5 3
