C# UDP Socket: Get receiver address

Question

I have an asynchronous UDP server class with a socket bound on IPAddress.Any, and I\'d like to know which IPAddress the received packet was sent to (...or received on). It

Answer 1

Adam

This is not tested...let's try

private void DoReceiveFrom(IAsyncResult iar){
//Get the received message.
Socket recvSock = (Socket)iar.AsyncState;
//EndPoint clientEP = new IPEndPoint(IPAddress.Any, 0);
Socket clientEP = recvSock.EndAccept(iar);
int msgLen = recvSock.EndReceiveFrom(iar, ref clientEP);
byte[] localMsg = new byte[msgLen];
Array.Copy(buffer, localMsg, msgLen);

//Start listening for a new message.
EndPoint newClientEP = new IPEndPoint(IPAddress.Any, 0);
udpSock.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref newClientEP, DoReceiveFrom, udpSock);

//Handle the received message
/*
Console.WriteLine("Recieved {0} bytes from {1}:{2} to {3}:{4}",
                  msgLen,
                  ((IPEndPoint)recvSock.RemoteEndPoint).Address,
                  ((IPEndPoint)recvSock.RemoteEndPoint).Port,
                  ((IPEndPoint)recvSock.LocalEndPoint).Address,
                  ((IPEndPoint)recvSock.LocalEndPoint).Port);
//Do other, more interesting, things with the received message.
*/
Console.WriteLine("Recieved {0} bytes from {1}:{2} to {3}",
                  msgLen,
                  ((IPEndPoint)recvSock.RemoteEndPoint).Address,
                  ((IPEndPoint)recvSock.RemoteEndPoint).Port,
                  clientEP.RemoteEP.ToString();
 }