MSP432E401Y: UDP: using sendto() without recvfrom()

Hi folks. I am trying to get a UDP send-only demo up and running. I started with the project at http://dev.ti.com/tirex/explore/node?node=ADB7cEDeelFwfWnYrD6CnQ__J4.hfJy__LATEST and have modified udpEcho.c so that it looks like:

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 *    from this software without specific prior written permission.
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/*
 *    ======== udpEcho.c ========
 *    Contains BSD sockets code.
 */

#include <pthread.h>
/* BSD support */
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <fcntl.h>

#include <string.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>

#include <ti/net/slnetutils.h>

#include <ti/display/Display.h>

/* Driver Header files */
#include <ti/drivers/GPIO.h>

/* Example/Board Header files */
#include "Board.h"

#define UDPPACKETSIZE 1472

extern Display_Handle display;

extern void fdOpenSession();
extern void fdCloseSession();
extern void *TaskSelf();

/*
 *  ======== echoFxn ========
 *  Echoes UDP messages.
 *
 */
void *echoFxn(void *arg0)
{
    int                bytesSent;
    int                bytesRcvd;
    int                status;
    int                sockfd;
    struct sockaddr_in localAddr;
    struct sockaddr_in clientAddr;
    socklen_t          addrlen;
    char               buffer[UDPPACKETSIZE];
    uint16_t           portNumber = *(uint16_t *)arg0;
    char mybuffer[256];

    fdOpenSession(TaskSelf());

    Display_printf(display, 0, 0, "UDP send demo started\n");

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd == -1) {
        Display_printf(display, 0, 0, "Error: socket not created.\n");
        goto shutdown;
    }

    memset(&localAddr, 0, sizeof(localAddr));
    localAddr.sin_family = AF_INET;
    localAddr.sin_addr.s_addr = htonl(INADDR_ANY);
    localAddr.sin_port = htons(portNumber);

    status = bind(sockfd, (struct sockaddr *)&localAddr, sizeof(localAddr));
    if (status == -1) {
        Display_printf(display, 0, 0, "Error: bind failed.\n");
        goto shutdown;
    }

//    if (fcntl(sockfd, F_SETFL, fcntl(sockfd, F_GETFL)|O_NONBLOCK) < 0) {
//        Display_printf(display, 0, 0, "Error: fcntl failed.\n");
//    }
//    char broadcast = '1';
//    if (setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, &broadcast, sizeof(broadcast)) < 0) {
//        Display_printf(display, 0, 0, "Error: setsockopt failed.\n");
//    }
//    bytesRcvd = recvfrom(sockfd, buffer, UDPPACKETSIZE, MSG_DONTWAIT, (struct sockaddr *)&clientAddr, &addrlen);
//    sprintf(mybuffer, "recvfrom returned (%d)", bytesRcvd);
//    Display_printf(display, 0, 0, mybuffer);

    recvfrom(sockfd, buffer, UDPPACKETSIZE, 0, (struct sockaddr *)&clientAddr, &addrlen);

    char* test_buffer = "This is a test!";

    Display_printf(display, 0, 0, "Going into loop.\n");
    while (1) {
        addrlen = sizeof(clientAddr);

        bytesSent = sendto(sockfd, test_buffer, strlen(test_buffer), 0, (struct sockaddr *)&clientAddr, addrlen);

        if (bytesSent < 0 || bytesSent != strlen(test_buffer)) {
            sprintf(mybuffer, "Error: sendto failed (%d)", bytesSent);
            Display_printf(display, 0, 0, mybuffer);
            // goto shutdown;
        }
        else {
            sprintf(mybuffer, "Send was successful.");
            Display_printf(display, 0, 0, mybuffer);
        }
    }

shutdown:
    if (sockfd != -1) {
        close(sockfd);
    }

    fdCloseSession(TaskSelf());

    return (NULL);
}

This code runs succesfully as expected, but if I remove the call to recvfrom(), then every call to sendto() in the loop fails. So my questions are:

Why is sendto() dependent on recvfrom() running first? 

How can I run sendto() without calling recvfrom()? Is there something that needs to be configured in the NDK stack?

I have also tried setting recvfrom() to be nonblocking, but have not been successful with that.