[En-Nut-Discussion] Sending broadcasts (WOL)

[Hugo Simon]

Hi,

I want to send MagicPackets with an Ethernut to power up a PC via WakeOnLAN.
But I cannot send anything to a computer which is switched of. Ethernut
cries out some ARP requests and get no answer. As I understand that I have
to send an UDP Broadcast to my subnet. But how?

I tried to send to addres 192.168.100.0 and 192.168.100.255. Subnetmask is
255.255.255.0 and Ethernut's IP is 192.168.100.48.

No difference. Ethernet always sends ARP requests. So I think I have to say
somehow that I want to send a broadcast, but how?

Can anybody help?

Here is my sending code:

 fprintf(stream,"Sending MagicPacket to %s\r\n",inet_ntoa(destIP));
 u_short wolport=1000;
 UDPSOCKET *udp;
 udp=NutUdpCreateSocket(wolport);
 if (!udp)
 {
  fputs("Internal error: Cannot create UDP socket",stream);
  free(buffer);
  return 1;
 }
 // for safety send the magic packet five times
  NutUdpSendTo(udp, destIP, wolport, buffer,sizeof(buffer));
 NutUdpDestroySocket(udp);

 free(buffer);