Get right ip adress of pc with multiple network cards

Hej All, I've an application that listens on a socket. The problem is that the pc has 2 network cards and is connected to the company netork and a plc network of course we have to listen/bind/... onto the IPAdress we got from the DHCP in the company network.

But when we do this:

System.Net.IPEndPoint(System.Net.Dns.GetHostEnt开发者_如何学运维ry(System.Net.Dns.GetHostName).AddressList(0)

We get the IP of the PLC network. Now we are looking for a way to find dynamically the right IPAdress. I got already the tip that you can bind a socket to the IPAdress (0:0:0:0) but we think it's a bit risky to do so.

Has anyone some ideas to solve this issue or some remarks about the 0:0:0:0?

Thanks in advance.

Jonathan

The only risk in binding to 0.0.0.0, or leaving it as the default, is that you will accept connections via both networks. Only you know whether that is a risk, i.e. whether there are things in the other network that you don't want connecting to you. Binding to 0.0.0.0, aka INADDR_ANY, is the default and near-universal practice in network programming.

Can't you loop through all adresses and use the one which is NOT 0.* and 168.* (or whatever the dhcp delivers...)

That should do in most(!) cases.

I let the user decide to what networkinterface he/she wanted to connect to and placed that in an AppSetting. Then I create a module that reads the config file to decide what networkinterface to connect to, and to check and get the IPAddress I use this code

in vb.net:

 Dim networkinterfaces() As NetworkInterface = NetworkInterface.GetAllNetworkInterfaces()
            Dim found As Boolean = False

            For Each ni As NetworkInterface In networkinterfaces
                If NetworkInterfaceName.Equals(ni.Name) Then
                    If ni.GetPhysicalAddress().ToString().Length > 0 Then
                        IPAddressFromNetworkCard = ni.GetIPProperties.UnicastAddresses(0).Address
                        found = True
                        Exit For
                    End If
                End If
            Next

in c# (some more tracing, but it almost does the same):

Console.WriteLine("Test get ip of interfacecard");
            Console.WriteLine("Give name of interfacecard:");
            string s = Console.ReadLine();


            List<NetworkInterface> nics = NetworkInterface.GetAllNetworkInterfaces().ToList<NetworkInterface>();
            Console.WriteLine(nics.Count + "  networkinterfaces found");

            bool found = false;
            foreach (NetworkInterface ni in nics)
            {
                Console.WriteLine("Available nic: " + ni.Name);
            }
            Console.WriteLine("");
            Console.WriteLine(String.Format("searching for: \"{0}\"", s));
            foreach (NetworkInterface ni in nics)
            {
                if (ni.Name.Equals(s))
                {
                    if (ni.GetPhysicalAddress().ToString().Length > 0)
                    {
                        Console.WriteLine("Network interface found, ipAddress: " + ni.GetIPProperties().UnicastAddresses[0].Address.ToString());
                        found = true;
                        break;
                    }
                }

            }
            if (!found)
                Console.WriteLine(String.Format("\"{0}\" not found", s));

            Console.ReadKey();