1 /* 2 * Copyright (c) 1982, 1986 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 * 6 * @(#)if_en.h 7.1 (Berkeley) 06/05/86 7 */ 8 9 /* 10 * Structure of a Ethernet header. 11 */ 12 struct en_header { 13 u_char en_shost; 14 u_char en_dhost; 15 u_short en_type; 16 }; 17 18 #define ENTYPE_PUP 0x0200 /* PUP protocol */ 19 #define ENTYPE_IP 0x0201 /* IP protocol */ 20 21 /* 22 * The ENTYPE_NTRAILER packet types starting at 23 * ENTYPE_TRAIL have (type-ENTYPE_TRAIL)*512 bytes 24 * of data followed by an Ethernet type (as given above) 25 * and then the (variable-length) header. 26 */ 27 #define ENTYPE_TRAIL 0x1000 /* Trailer type */ 28 #define ENTYPE_NTRAILER 16 29 30 #define EN_BROADCAST 0 /* Hardware broadcast address */ 31