igmp.igmp.group.s_addr = igmptable[slot].group.s_addr;
igmp.igmp.chksum = ipchksum ( &igmp.igmp, sizeof ( igmp ) );
ip_transmit ( sizeof ( igmp ), &igmp );
igmp.igmp.group.s_addr = igmptable[slot].group.s_addr;
igmp.igmp.chksum = ipchksum ( &igmp.igmp, sizeof ( igmp ) );
ip_transmit ( sizeof ( igmp ), &igmp );