INADDR_ALLHOSTS_GROUP
m.imr_multiaddr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
m.imr_multiaddr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
send_adv(ifp, htonl(INADDR_ALLHOSTS_GROUP),
igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);