anchor.diff:             fun() ->
                      ?TT(?SECS(10)),
                      Recv      = fun(Sock, To) -> socket:recvmsg(Sock, To) end,
  -                   InitState = #{domain => inet6,
  -                                 recv   => Recv},
  +                   InitState = #{domain   => inet6,
  +                                 protocol => udp,
  +                                 recv     => Recv},
                      ok = sc_lc_receive_response_udp(InitState)
              end).
   
  
positive.code:            fun() -> has_support_ipv6() end,
             fun() ->
                     Recv      = fun(Sock, To) -> socket:recvfrom(Sock, [], To) end,
                     InitState = #{domain => inet6,
                                   recv   => Recv},
                     ok = sc_lc_receive_response_udp(InitState)
             end).
  
  
negative.code:         {ok, Port} ->
              Port;
          {error, Reason} ->
              i("sock_bind -> error: "
                "~n   SockAddr: ~p"
                "~n   Reason:   ~p", [SockAddr, Reason]),
              ?FAIL({bind, Reason})
      catch
          C:E:S ->
  