[codeprada]

Hey guys, I'm working on a Messenger system and I'm using UDP on the client side to detect which host the server is running from. It works fine but on Windows 7 systems administrator privileges are needed to listen on ports. The machines the clients are to run on require the Administrator password to do so. It does not however need the administrator password on the TCP side since the server is doing the listening. Is there another method or solution for this? Would not mind another method of detecting the server either. By the way it's a LAN based messenger.

[Skydiver]

Sort of a tangential question. If you are using UDP, then more likely than not, you have a peer-to-peer system. Why do you need a server? Typically, when you have server, then you have the clients make TCP connections to the server.

[baavgai]

UDP? Are you doing some kind of broadcast for discover? If not, you should. If you are, what's the code? It's odd you'd get locked down for that. Perhaps you want a different port; some have specific security considerations.

Alternates? On a Windows domain you could just ask active directory. Put servers that are available in a group.

[codeprada]

@Skydiver No it's not a peer-to-peer system. A central server is involved that receives all messages and sends them to the appropriate client.

@baavgai Yep the UDP is just for discovery purposes. Wanted to save my users the hassle of selecting the host because they aren't computer savie. Even the word Port baffles them so I decided to let the client send out a UDP datagram to all the computers on the network and whichever sends back the right response has the server. The code I was using is this:

private void Search()
{

	UdpClient udp_client = new UdpClient(9999); //new UdpClient(Protocol.IM_Message.UDP_PORT);
	
	IPEndPoint ip_endpoint;// = new IPEndPoint(IPAddress.Any, 0);
	byte[] data = ASCIIEncoding.ASCII.GetBytes(IM_Message.MESSAGE_TYPE_HELLO);

	foreach (KeyValuePair<string, IPAddress> p in hostToIP)
	{
		ip_endpoint = new IPEndPoint(p.Value, 9999);

		UdpState s = new UdpState();
		s.e = ip_endpoint;
		s.u = udp_client;

		messageReceived = false;
		udp_client.Connect(ip_endpoint);
		udp_client.Send(data, data.Length);
		udp_client.BeginReceive(new AsyncCallback(ReceiveCallback), s);

		Thread.Sleep(300);
		if (messageReceived)
		{
			
			server = p.Value;
			break;
		}
	}
}

Fairly new to this side of C# so bare with me. The application requested administrator rights when the BeginReceive method is called.

After doing some reading I took a whole new route. I decided to add the client and server to the same MulticastGroup. Turns out administrative rights aren't required with that method so it's working now.