Dns.GetHostAddress(hostname) No such device or add

I have a .net core 2.0 project which is trying to get Host name and Host IP address from a linux machine. The program runs well in Mac OS and Windows but not on linux - Ubuntu 16.04

public class Program
{
    public static void Main(string[] args)
    {
        var HostName = Dns.GetHostName();
        Console.WriteLine("Host name : " + HostName);
        var HostAddress = GetHostAddress(HostName);
        Console.WriteLine("Host address : " + HostAddress);
    }

    private static string GetHostAddress(string hostName)
    {
        try
        {
            var addressList = Dns.GetHostAddresses(hostName);

            foreach (IPAddress address in addressList)
            {
                Console.WriteLine("IP Address : " + address.ToString());
                if (address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
                {
                    string ip = address.ToString();
                    if (!ip.StartsWith("127."))
                        return ip;
                }
            }

            return "127.0.0.1";
        }
        catch (Exception e)
        {
            Console.WriteLine(e);
            throw;
        }

    }
}

The exception I got is

ubuntu@ip-10-40-121-185:~/home/IP$ dotnet IP.dll

Host name : ip-10-40-121-185

System.Net.Internals.SocketExceptionFactory+ExtendedSocketException (0x00000005): No such device or address

at System.Net.Dns.InternalGetHostByName(String hostName, Boolean includeIPv6)

at System.Net.Dns.GetHostAddresses(String hostNameOrAddress)

at IP.Program.GetHostAddress(String hostName) in /Users/jliu/RiderProjects/IpTest/IP/Program.cs:line 34

Unhandled Exception: System.Net.Internals.SocketExceptionFactory+ExtendedSocketException: No such device or address

at System.Net.Dns.InternalGetHostByName(String hostName, Boolean includeIPv6)

at System.Net.Dns.GetHostAddresses(String hostNameOrAddress)

at IP.Program.GetHostAddress(String hostName) in /Users/jliu/RiderProjects/IpTest/IP/Program.cs:line 52

at IP.Program.Main(String[] args) in /Users/jliu/RiderProjects/IpTest/IP/Program.cs:line 20 Aborted (core dumped)

Any idea how to fix it or any alternative to get IP on a linux machine? Thanks.

Get answer from another thread Get local IP address which works for me

Thanks for the solution from @Gerardo H https://stackoverflow.com/a/28621250/4861127

    internal static string GetLocalIPv4(NetworkInterfaceType _type)
    {
        string output = "";
        foreach (NetworkInterface item in NetworkInterface.GetAllNetworkInterfaces())
        {
            if (item.NetworkInterfaceType == _type && item.OperationalStatus == OperationalStatus.Up)
            {
                IPInterfaceProperties adapterProperties = item.GetIPProperties();

                if (adapterProperties.GatewayAddresses.FirstOrDefault() != null)
                {
                    foreach (UnicastIPAddressInformation ip in adapterProperties.UnicastAddresses)
                    {
                        if (ip.Address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
                        {
                            output = ip.Address.ToString();
                        }
                    }
                }
            }
        }

        return output;
    }