1 /* 2 * Copyright (c) 1982, 1986 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)if_en.h 7.3 (Berkeley) 06/28/90 8 */ 9 10 /* 11 * Structure of a Ethernet header. 12 */ 13 struct en_header { 14 u_char en_shost; 15 u_char en_dhost; 16 u_short en_type; 17 }; 18 19 #define ENTYPE_PUP 0x0200 /* PUP protocol */ 20 #define ENTYPE_IP 0x0201 /* IP protocol */ 21 22 /* 23 * The ENTYPE_NTRAILER packet types starting at 24 * ENTYPE_TRAIL have (type-ENTYPE_TRAIL)*512 bytes 25 * of data followed by an Ethernet type (as given above) 26 * and then the (variable-length) header. 27 */ 28 #define ENTYPE_TRAIL 0x1000 /* Trailer type */ 29 #define ENTYPE_NTRAILER 16 30 31 #define EN_BROADCAST 0 /* Hardware broadcast address */ 32