/* * Copyright (c) 1988 Stephen Deering. * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Stephen Deering of Stanford University. * * %sccs.include.redist.c% * * @(#)igmp.h 8.1 (Berkeley) 06/10/93 */ /* Internet Group Management Protocol (IGMP) definitions. */ /* * IGMP packet format. */ struct igmp { u_char igmp_type; /* version & type of IGMP message */ u_char igmp_code; /* unused, should be zero */ u_short igmp_cksum; /* IP-style checksum */ struct in_addr igmp_group; /* group address being reported */ }; /* (zero for queries) */ #define IGMP_MINLEN 8 #define IGMP_HOST_MEMBERSHIP_QUERY 0x11 /* message types, incl. version */ #define IGMP_HOST_MEMBERSHIP_REPORT 0x12 #define IGMP_DVMRP 0x13 /* for experimental multicast */ /* routing protocol */ #define IGMP_MAX_HOST_REPORT_DELAY 10 /* max delay for response to */