| net/if.h | Basic ifnet facilities and data structures, including the ifnet structure, the basic driver interface object. |
| net/if_types.h | Constants for interface types, used in decoding address headers. |
| sys/mbuf.h | The mbuf structure with related constants and macros, and declarations of functions to allocate, manipulate, and free mbuf objects. |
| net/netisr.h | Declarations related to software interrupts, including schednetisr() to schedule an interrupt, and the IP input queue ipintrq. |
| net/multi.h | Routines defining a generic filter for use by drivers whose devices cannot perfectly filter multicast packets. |
| net/soioctl.h | Socket ioctl() function numbers, some of which reach a driver for action. |
| net/raw.h | The interface to the raw protocol family members snoop and drain. |
| net/if_arp.h | Generic ARP declarations. |
| netinet/if_ether.h | Essential declarations for Ethernet drivers, including ARP protocol for Ethernet. |
| sys/dlsap_register.h | DLPI interface declarations. |