scope6_addr2default
scopeid = scope6_addr2default(in6);
addr->sin6_scope_id = scope6_addr2default(&addr->sin6_addr);
addr->sin6_scope_id = scope6_addr2default(&addr->sin6_addr);
dst->sin6_scope_id = scope6_addr2default(&dst->sin6_addr);
u_int32_t scope6_addr2default (struct in6_addr *);