Question

I have a C# function which return Local IP Address.

private string GetLocalIPByHostName()
    {
        string host = Dns.GetHostName();
        string LocalIP = string.Empty;
        IPHostEntry ip = Dns.GetHostEntry(host);
        foreach (IPAddress _IPAddress in ip.AddressList)
        {
            if (_IPAddress.AddressFamily.ToString() == "InterNetwork")
            {
                LocalIP = _IPAddress.ToString();

            }
        }
        return LocalIP;
    }

By using this local IP address, I tried to get MAC Address.

protected string GetMACAddressByIP(string ip)
    {
        try
        {
            ManagementObjectSearcher query= new ManagementObjectSearcher("SELECT * FROM Win32_NetworkAdapterConfiguration");
            ManagementObjectCollection queryCollection = query.Get();
            bool Found = false;
            foreach(ManagementObject _ManagementObject in queryCollection)
            {
                if (_ManagementObject["IPAddress"] != null)
                {
                    string _IPAddress;
                    _IPAddress = string.Join(".", (string[])_ManagementObject["IPAddress"]);

                    if(!_IPAddress.Equals(""))
                    {
                        if(_IPAddress.Equals(ip.Trim()))
                        {
                                Found = true;
                        }
                    }

                    if(Found == true)
                    {
                        if (_ManagementObject["macaddress"] != null)
                        {
                            if (!_ManagementObject["macaddress"].Equals(""))
                            {
                                return (string)_ManagementObject["macaddress"];
                            }
                        }
                    }
                    else
                    {
                        Found = false;
                    }
                }
            }

            MessageBox.Show("No Mac Address Found");
            return "";
        }
        catch(Exception ex)
        {
            MessageBox.Show(ex.Message);
            return "";
        }
    }

Two of the functions work correctly.
But what I would like to do is getting other PC’s IP Address at the same LAN network.
Then, If I get those IP Addresses , that will be input value to my

GetMACAddressByIP(string ip)

function.

But my problem is I don’t know how to get other pc IP Address.

private List<string> GetRemoteIPs(string LocalIPAddress)
    {
        List<string> RemoteIPs = new List<string>();

             /*** Here code will be as suggestion of yours.  ****/    

        return RemoteIPs;
    }

Then, Next Question is
Is this possible to get MAC Address of PC which is already turn off ?

Every solution will be really appreciated.

Answer 1

    // Get all active IP connections on the network
    private void btnSearch_Click(object sender, EventArgs e)
    {
        System.Net.NetworkInformation.IPGlobalProperties network = System.Net.NetworkInformation.IPGlobalProperties.GetIPGlobalProperties();
        System.Net.NetworkInformation.TcpConnectionInformation[] connections = network.GetActiveTcpConnections();

        foreach (System.Net.NetworkInformation.TcpConnectionInformation connection in connections)
        {

        }
    }