UDP Broadcast recieve

[Dave]

I can't figure out why my code does not recieve the message. The only
message that it receives is the one going out from my machine. I am
suppose to send out a message to a server. Upon receiving that message
on the server side the server is suppose to send a message back. I
can't get my app to receive that message. It only receives the one
being sent out by my machine. I know that the server is sending out a
message because there is another app in vb that receives the message.
Here is my code:

private constructor()
{
iepSend = new IPEndPoint(IPAd dress.Broadcast , UDP_PORT);
epSend = (EndPoint)iepSe nd;

iepRx = new IPEndPoint(IPAd dress.Any, UDP_PORT);
epRx = (EndPoint)iepRx ;

m_SocketUDP = new Socket(AddressF amily.InterNetw ork, SocketType.Dgra m,
ProtocolType.Ud p);
m_SocketUDP.Set SocketOption(So cketOptionLevel .Socket,
SocketOptionNam e.Broadcast, 1);
m_SocketUDP.Set SocketOption(So cketOptionLevel .Socket,
SocketOptionNam e.ReuseAddress, 1);
m_SocketUDP.Con nect(epSend);

udpRxSocket = new Socket(iepRx.Ad dressFamily, SocketType.Dgra m,
ProtocolType.Ud p);
udpRxSocket.Set SocketOption(So cketOptionLevel .Socket,
SocketOptionNam e.ReuseAddress, 1);
udpRxSocket.Set SocketOption(So cketOptionLevel .Socket,
SocketOptionNam e.ReceiveTimeou t, 5000);
udpRxSocket.Bin d(iepRx);

SetupReceiveCal lbackUDP()
}

private void SetupReceiveCal lbackUDP()
{
AsyncCallback receiveData = new AsyncCallback(O nReceiveData);
udpRxSocket.Beg inReceiveFrom(b uffer, 0, buffer.Length,
SocketFlags.Non e, ref epRx, receiveData, udpRxSocket);
}

private void OnReceiveData(I AsyncResult ar)
{
Socket socket = (Socket)ar.Asyn cState;

try
{
int nBytesRec = socket.EndRecei veFrom(ar, ref epRx);
if(nBytesRec > 0)
{
string Received = Encoding.ASCII. GetString(buffe r, 0, nBytesRec);
//Received += socket.RemoteEn dPoint.ToString ();
WriteOutput("Re ceived Data: " + Received);
SetupReceiveCal lbackUDP();
}
}
catch(Exception e)
{
WriteOutput("Er ror. "+ e.Message);
}
}

Anyone know whats wrong?

[Jani Järvinen [MVP]]

Dave,

I can't figure out why my code does not recieve the message.

Unfortunately I don't have the time to review your code, but two things come
into mind architecture-wise: firewall settings and network errors.

Years ago I wrote a simple system to broadcast UDP messages to a local
subnet. This solution worked well when the 10 MB Ethernet network wasn't
busy, but when there were lots of traffic, those little UDP messages simply
were "missing in action". The same thing might happen to you.

Also, if it only happens that the server sees your client's messages but not
the other way around, check the (desktop)firewa ll settings on the server
(for outbound UDP blocking) and on your client (for incoming blocks).

Hope this helps.

--
Regards,

Mr. Jani Järvinen
C# MVP
Helsinki, Finland
ja***@removethi s.dystopia.fi
http://www.saunalahti.fi/janij/