How do I determine the local host’s IPv4 addresses?

Question

How do I get only Internet Protocol version 4 addresses from Dns.GetHostAddresses()? I have the code below, and it gives me IPv4 and IPv6 addresses. I have to m

Answer 1

I use this helper method that returns the first active IPV4 address after filtering out the IPV6 and Loopback once

    public static IPAddress GetLocalIPAddress()
    {
        IPAddress result = null;
        IPHostEntry iphostentry = Dns.GetHostEntry(Dns.GetHostName());
        IPAddress[] ipv4Address = Array.FindAll(iphostentry.AddressList, add => add.AddressFamily == AddressFamily.InterNetwork && !IPAddress.IsLoopback(add));
        if (ipv4Address.Length > 0 )
        {
            result =ipv4Address[0];
        }
        return result;
    }

Answer 2

Here's a function I use:

public static string GetIP4Address()
{
    string IP4Address = String.Empty;

    foreach (IPAddress IPA in Dns.GetHostAddresses(Dns.GetHostName()))
    {
        if (IPA.AddressFamily == AddressFamily.InterNetwork)
        {
            IP4Address = IPA.ToString();
            break;
        }
    }

    return IP4Address;
}

---

As an enumerable:

public static IEnumerable<string> GetIP4Addresses()
{
    return Dns.GetHostAddresses(Dns.GetHostName())
        .Where(IPA => IPA.AddressFamily == AddressFamily.InterNetwork)
        .Select(x => x.ToString());
}

Answer 3

For me the cleaner solution would be:

 public static string GetLocalIP() 
        {
            string ipv4Address = String.Empty;

            foreach (IPAddress currentIPAddress in Dns.GetHostAddresses(Dns.GetHostName()))
            {
                if (currentIPAddress.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
                {
                    ipv4Address = currentIPAddress.ToString();
                    break;
                }
            }

            return ipv4Address;
        }

Answer 4

Here is a code to find the first connected IPv4 by using for loop :

        IPAddress ipAddress = null;
        IPAddress[] localIPs = Dns.GetHostAddresses(Dns.GetHostName());           

        for (int i=0 ; i<localIPs.Length ; i++)
        {
            if (localIPs[i].AddressFamily == AddressFamily.InterNetwork)
            {
                ipAddress = localIPs[i];
                break;
            }                
        }

Answer 5

Write locaIPs.Where(ip => ip.AddressFamily == AddressFamily.InterNetwork)