Can't receive UDP packets over broadcast address, ArtNet

Question

I am trying to receive UDP packets on the raspberry pi. I have created a simple java program to connect the network. (I have all relevant code below)

String myNetworkAddress = "10.0.0.11";
String myBroadcastAddress = "10.255.255.255";
// Setup network connection
    try {
        InetAddress nicAddress = InetAddress.getByName(myNetworkAddress);
        InetAddress baddr = InetAddress.getByName(myBroadcastAddress);
        dmx = new ArtNet(nicAddress, baddr);

        udpsocket = new DatagramSocket(null);
        udpsocket.setReuseAddress(true);
        udpsocket.bind(new InetSocketAddress(nicAddress, dmx.getPort()));
        udpsocket.setBroadcast(true);
        udpsocket.setSoTimeout(1000);
        System.out.println("Opened socket " + udpsocket.getLocalAddress() + ":" + udpsocket.getLocalPort());
    } catch (Exception e) {
        System.out.println("can't open socket " + e);
    }

while (true) {
        if (udpsocket != null) {
            if (dmx.readPacket(udpsocket)) {
                i = dmx.getPacket();
// read packet and process 
 }
 }
 }

I am not able to receive anything from the broadcast, on a raspberry pi. But when I run this code on another computer, I am able to receive packets from the broadcast. This leaves me to believe that java is not given access to creating a socket, binding the port and that it is not the code but a security measure on the raspberry pi.

Things that I have tried:

• running program as sudo,
• updating permissions,
• changing user permissions, and
• changing IP tables to allow for the port 6454.

Ifconfig:

eth0      Link encap:Ethernet  HWaddr b8:27:eb:11:11:11
          inet addr:192.168.1.48  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:351 errors:0 dropped:0 overruns:0 frame:0
          TX packets:376 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:25333 (24.7 KiB)  TX bytes:77137 (75.3 KiB)

dhclient.conf (Used when no router/dhcp server is available, connection is made between a computer and raspberry pi with a static ip):

timeout 10;
lease {
    interface "eth0";
    fixed-address 10.0.0.10;
    option broadcast-address 10.255.255.255;
    option subnet-mask 255.0.0.0;
    option host-name "node.local";
    renew 2 2022/1/1 00:00:01;
    rebind 2 2022/1/1 00:00:01;
    expire 2 2022/1/1 00:00:01;
}

With no luck. any advice or help would be greatly appreciated.

Answer 1

By Binding on the NicAddress, it only accepts incoming packets from the network address. Binding to 0.0.0.0 Will allow incoming pacts from the broadcast IP as well as other IP addresses