Const
  adapterIP = '127.0.0.1';
  multiGroup = '227.0.0.2';
  listenPort: Word = 8167;
  Max_Size = 512;

Var
  wData: WSADATA;
  aSock: TSOCKET;
  listener: sockaddr_in;

  aStr: String;
  t: Integer;
Begin
  ZeroMemory(@wData, SizeOf(wData));

  Try
    If WSAStartup(MAKEWORD(2, 2), wData) <> NO_ERROR Then
      Raise Exception.Create('Error at WSAStartup');
    Try
      WriteLn(wData.szDescription, ' is ', wData.szSystemStatus, '.');

      aSock := Socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); //Говорим, какой сокет мы хотим
      WSACheck(aSock <> INVALID_SOCKET);
      Try
        listener.sin_family := AF_INET;  // говорим, что будем слушать
        listener.sin_addr.S_addr := inet_addr(adapterIP);
        listener.sin_port := htons(listenPort);

        WSACheck(bind(aSock, listener, SizeOf(listener)) <> SOCKET_ERROR); //привязываемся к порту

        Repeat
          SetLength(aStr, Max_Size);
          ZeroMemory(PChar(aStr), Max_Size);
          t := recvfrom(aSock, PChar(aStr)^, Max_Size, 0, PSockAddrIn(Nil)^, PInteger(Nil)^);
          WSACheck(t <> SOCKET_ERROR);
          SetLength(aStr, t);
          WriteLn('Received: ', aStr);
        Until t = 0;

      Finally
        CloseSocket(aSock);
      End;
    Finally
      WSACleanup;
    End;