k_leave
extern void k_leave(u_int32_t grp, u_int32_t ifa);
k_leave(dvmrp_group, v->uv_lcl_addr);
k_leave(allrtrs_group, v->uv_lcl_addr);
if (IN_MULTICAST(ntohl(raddr))) k_leave(raddr, lcl_addr);
} else k_leave(resp_cast, lcl_addr);