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can receive broadcast messages

I am trying to write code the receives broadcast messages coming from another app. using wireShark, I can see that they are sent to 255.255.255.255:300.
I tried the following code:
IPEndPoint ServerEndPoint = new IPEndPoint(IPAddress.Any, 3000);
Socket WinSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
WinSocket.Bind(ServerEndPoint);
byte[] data = new byte[10];
Console.Write("Waiting for client");
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
EndPoint Remote = (EndPoint)(sender);
int recv = WinSocket.ReceiveFrom(data, ref Remote);
Console.WriteLine("Message received from {0}:", Remote.ToString());
string str = Encoding.ASCII.GetString(data, 0, recv);
but when my app reached to the "bind" command there is an error message:
"Only one usage of each socket address (protocol/network address/port) is normally permitted"
if I change the port there is no error but I catch nothing.
Please advice

UDP Multicast not receiving data

I'm trying to write a simple client to receive multicast data. I've tried many different iterations and none of them work. The environment that I am using is .netcore 2.2.2 and in a linux environment. I can see that the data is being sent to the proper interface via tcpdump but my client always gets stuck at the receive. I also have a program that was written in Java by a previous developer which properly receives data from interfaces below so I can confirm that the route does indeed work.
Attempt #1
mcastSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Dgram,
ProtocolType.Udp);
IPAddress localIPAddr = IPAddress.Parse("10.51.254.2");
EndPoint localEP = (EndPoint)new IPEndPoint(localIPAddr, mcastPort);
mcastSocket.Bind(localEP);
mcastOption = new MulticastOption(mcastAddress, localIPAddr);
mcastSocket.SetSocketOption(SocketOptionLevel.IP,
SocketOptionName.AddMembership,
mcastOption);
EndPoint remoteEp = new IPEndPoint(mcastAddress, mcastPort);
// I have tried using (localIPAddr, mcastPort), (IPAddress.Any, 0),
// (localIPAddr, 0), (IPAddress.Any, mcastPort)
byte[] arr = new byte[4096];
Console.WriteLine("Socket setup");
var receivedBytes = mcastSocket.ReceiveFrom(arr, ref remoteEp );
Console.WriteLine("Got data");
Attempt#2
UdpClient client = new UdpClient();
client.ExclusiveAddressUse = false;
IPEndPoint localEp = new IPEndPoint(IPAddress.Parse("10.51.254.2"), 14382);
client.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
client.ExclusiveAddressUse = false;
client.Client.Bind(localEp);
client.JoinMulticastGroup(IPAddress.Parse("224.0.31.130"), IPAddress.Parse("10.51.254.2"));
Console.WriteLine("Listening this will never quit so you will need to ctrl-c it");
IPEndPoint remoteEp = new IPEndPoint(IPAddress.Parse("224.0.31.130"), 14382);
EndPoint remoteEndPoint = (EndPoint) new IPEndPoint(IPAddress.Any, 0);
while (true)
{
Byte[] data = client.Receive(ref remoteEndPoint);
Console.WriteLine("got data");
}
Any help would be greatly appreciated.
FIXED using the following code
try
{
mcastSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
IPAddress localIPAddr = IPAddress.Parse("10.51.254.2");
IPEndPoint localEP = new IPEndPoint(IPAddress.Any, mcastPort);
mcastSocket.Bind(localEP);
MulticastOption option = new MulticastOption(mcastAddress, localIPAddr);
mcastSocket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership, option);
EndPoint remoteEp = new IPEndPoint(localIPAddr, mcastPort);
byte[] arr = new byte[4096];
while (true)
{
var receivedBytes = mcastSocket.ReceiveFrom(arr, ref remoteEp);
Console.WriteLine($"Got data {receivedBytes}");
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}

How can I add SSL encryption to available TCP/IP socket

I am going to upgrade a system which used TCP connection without SSL. I want to add SSL encryption to the current connection without changing much in code. This is what there was previously in the code.
IPAddress ipAddress = IPAddress.Parse(IpAddress);
IPEndPoint remoteEP = new IPEndPoint(ipAddress, Port);
// Create a TCP/IP socket.
var client = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
client.BeginConnect(remoteEP,new AsyncCallback(ConnectCallback), client);
What I tried is this,
IPAddress ipAddress = IPAddress.Parse(IpAddress);
IPEndPoint remoteEP = new IPEndPoint(ipAddress, Port);
// Create a TCP/IP socket.
var client = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
client.BeginConnect(remoteEP, new AsyncCallback(ConnectCallback), client);
while (!client.Connected) { }
NetworkStream stream = new NetworkStream(client);
SslStream ssl = new SslStream(stream, false, ValidateServerCertificate);
But this is not doing what I need. At least ValidateServerCertificate delegate is not called.
What's wrong with my code?
IMPORTANT
I cannot remove this socket named client during the change because it will affect lot of other codes.

Sending and Receiving UDP packets

The following code sends a packet on port 15000:
int port = 15000;
UdpClient udp = new UdpClient();
//udp.EnableBroadcast = true; //This was suggested in a now deleted answer
IPEndPoint groupEP = new IPEndPoint(IPAddress.Broadcast, port);
string str4 = "I want to receive this!";
byte[] sendBytes4 = Encoding.ASCII.GetBytes(str4);
udp.Send(sendBytes4, sendBytes4.Length, groupEP);
udp.Close();
However, it's kind of useless if I can't then receive it on another computer. All I need is to send a command to another computer on the LAN, and for it to receive it and do something.
Without using a Pcap library, is there any way I can accomplish this? The computer my program is communicating with is Windows XP 32-bit, and the sending computer is Windows 7 64-bit, if it makes a difference. I've looked into various net send commands, but I can't figure them out.
I also have access to the computer (the XP one)'s local IP, by being able to physically type 'ipconfig' on it.
EDIT: Here's the Receive function I'm using, copied from somewhere:
public void ReceiveBroadcast(int port)
{
Debug.WriteLine("Trying to receive...");
UdpClient client = null;
try
{
client = new UdpClient(port);
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
IPEndPoint server = new IPEndPoint(IPAddress.Broadcast, port);
byte[] packet = client.Receive(ref server);
Debug.WriteLine(Encoding.ASCII.GetString(packet));
}
I'm calling ReceiveBroadcast(15000) but there's no output at all.

Here is the simple version of Server and Client to send/receive UDP packets
Server
IPEndPoint ServerEndPoint= new IPEndPoint(IPAddress.Any,9050);
Socket WinSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
WinSocket.Bind(ServerEndPoint);
Console.Write("Waiting for client");
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0)
EndPoint Remote = (EndPoint)(sender);
int recv = WinSocket.ReceiveFrom(data, ref Remote);
Console.WriteLine("Message received from {0}:", Remote.ToString());
Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));
Client
IPEndPoint RemoteEndPoint= new IPEndPoint(
IPAddress.Parse("ServerHostName"), 9050);
Socket server = new Socket(AddressFamily.InterNetwork,
SocketType.Dgram, ProtocolType.Udp);
string welcome = "Hello, are you there?";
data = Encoding.ASCII.GetBytes(welcome);
server.SendTo(data, data.Length, SocketFlags.None, RemoteEndPoint);

UDP client in C#

Am trying to make a simple UDP application using C sharp,nothing sophisticated,connect,send some text,and receive it! but it keeps throwing this exception!
"An existing connection was forcibly closed by the remote host"!
The code :
byte[] data = new byte[1024];
IPEndPoint ipep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9050);
Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
string welcome = "Hello, are you there?";
data = Encoding.ASCII.GetBytes(welcome);
server.SendTo(data, data.Length, SocketFlags.None, ipep);
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
EndPoint tmpRemote = (EndPoint)sender;
data = new byte[1024];
int recv = server.ReceiveFrom(data, ref tmpRemote);
Console.WriteLine("Message received from {0}:", tmpRemote.ToString());
Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));
Console.WriteLine("Stopping client");
server.Close();
thanks =)

You should tell the system that you are listening for UDP packets on port 9050 before you call Receive.
Add server.Bind(ipep); after Socket server = new Socket(...);

Have you tried checking that the IP address is valid and the port is not being used for something else?
Windows:
Start > Run > "cmd" > "ipconfig".

Try turning off your firewall software.

If you do not know the IP of the answering server, you better do:
recv = server.Receive(data);
Here is my suggetion to your code. You can use a do-while loop using a condition (in my example it is an infinite loop):
byte[] data = new byte[1024];
IPEndPoint ipep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9050);
Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
string welcome = "Hello, are you there?";
data = Encoding.ASCII.GetBytes(welcome);
server.ReceiveTimeout = 10000; //1second timeout
int rslt = server.SendTo(data, data.Length, SocketFlags.None, ipep);
data = new byte[1024];
int recv = 0;
do
{
try
{
Console.WriteLine("Start time: " + DateTime.Now.ToString());
recv = server.Receive(data); //the code will be stoped hier untill the time out is passed
}
catch { }
} while (true); //carefoul! infinite loop!
Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));
Console.WriteLine("Stopping client");
server.Close();