MSP432E401Y: NDK for Broadcast UDP TIRTOS

As far as I understand (i.e, this seemed to work), to send a multicast, you just send to the correct multicast address.

e.g.

const char *   MULTICAST = "224.0.1.129";



	struct sockaddr_in clientAddr;
	socklen_t addrlen = sizeof(clientAddr);

	clientAddr.sin_family      = AF_INET;
	clientAddr.sin_port        = htons(EVENT_PORT);
	clientAddr.sin_addr.s_addr = inet_addr(MULTICAST);   // The required IP address

	int bytesSent = sendto(LocalFD, pBuffer, bytesToSend, 0,  (struct sockaddr *)&clientAddr, addrlen);
	if (bytesSent < 0)
	{
		Display_printf(display, 0, 0, "Error: sendto failed.");
	}

To receive from a multicast, you must register with the multicast first:

/// A temporary struct used for setting multicast address.
typedef struct my_ip_mreq
{
    struct in_addr  imr_multiaddr;  /**< IP Address of the group     */
    struct in_addr  imr_interface;  /**< IP Address of the interface */
}my_ip_mreq;


    struct my_ip_mreq mreq;


    mreq.imr_multiaddr.s_addr = inet_addr(MULTICAST);
    mreq.imr_interface.s_addr = htonl(INADDR_ANY);
    int res = setsockopt(LocalFD, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
    Display_printf(display, 0, 0, "Join 1st multicast on PTP port returned %d", res);

    /* Set the SO_REUSEPORT option.  */
    int optval = 1;
    res = setsockopt(LocalFD, SOL_SOCKET, SO_REUSEPORT, &optval, sizeof(optval));
    Display_printf(display, 0, 0, "Set SO_REUSEPORT on PTP port returned %d", res);

Thanks.. That's just the ticket for multicast reception.