Get public/external IP address?

Question

I cant seem to get or find information on finding my routers public IP? Is this because it cant be done this way and would have to get it from a website?

Answer 1

checkip.dyndns.org is not always works correctly. For example, for my machine it shows internal after-NAT address:

Current IP Address: 192.168.1.120

I think its happening, because of I have my local DNS-zone behind NAT, and my browser sends to checkip its local IP address, which is returned back.

Also, http is heavy weight and text oriented TCP-based protocol, so not very suitable for quick and efficient regular request for external IP address. I suggest to use UDP-based, binary STUN, especially designed for this purposes:

http://en.wikipedia.org/wiki/STUN

STUN-server is like "UDP mirror". You looking to it, and see "how I looks".

There is many public STUN-servers over the world, where you can request your external IP. For example, see here:

http://www.voip-info.org/wiki/view/STUN

You can download any STUN-client library, from Internet, for example, here:

http://www.codeproject.com/Articles/18492/STUN-Client

And use it.

Answer 2

string pubIp =  new System.Net.WebClient().DownloadString("https://api.ipify.org");

Answer 3

Expanding on this answer by @suneel ranga:

static System.Net.IPAddress GetPublicIp(string serviceUrl = "https://ipinfo.io/ip")
{
    return System.Net.IPAddress.Parse(new System.Net.WebClient().DownloadString(serviceUrl));
}

Where you would use a service with System.Net.WebClient that simply shows the IP address as a string and uses the System.Net.IPAddress object. Here are a few such services*:

• https://ipinfo.io/ip/
• https://api.ipify.org/
• https://icanhazip.com/
• https://checkip.amazonaws.com/
• https://wtfismyip.com/text

* Some services were mentioned in this question and from these answers from superuser site.

Answer 4

Most of the answers have mentioned http://checkip.dyndns.org in solution. For us, it didn't worked out well. We have faced Timemouts a lot of time. Its really troubling if your program is dependent on the IP detection.

As a solution, we use the following method in one of our desktop applications:

    // Returns external/public ip
    protected string GetExternalIP()
    {
        try
        {
            using (MyWebClient client = new MyWebClient())
            {
                client.Headers["User-Agent"] =
                "Mozilla/4.0 (Compatible; Windows NT 5.1; MSIE 6.0) " +
                "(compatible; MSIE 6.0; Windows NT 5.1; " +
                ".NET CLR 1.1.4322; .NET CLR 2.0.50727)";

                try
                {
                    byte[] arr = client.DownloadData("http://checkip.amazonaws.com/");

                    string response = System.Text.Encoding.UTF8.GetString(arr);

                    return response.Trim();
                }
                catch (WebException ex)
                {
                    // Reproduce timeout: http://checkip.amazonaws.com:81/

                    // trying with another site
                    try
                    {
                        byte[] arr = client.DownloadData("http://icanhazip.com/");

                        string response = System.Text.Encoding.UTF8.GetString(arr);

                        return response.Trim();
                    }
                    catch (WebException exc)
                    { return "Undefined"; }
                }
            }
        }
        catch (Exception ex)
        {
            // TODO: Log trace
            return "Undefined";
        }
    }

Good part is, both sites return IP in plain format. So string operations are avoided.

To check your logic in catch clause, you can reproduce Timeout by hitting a non available port. eg: http://checkip.amazonaws.com:81/

Answer 5

Or this, it works quite well i think for what i needed. It's from here.

public IPAddress GetExternalIP()
{
    WebClient lol = new WebClient();
    string str = lol.DownloadString("http://www.ip-adress.com/");
    string pattern = "<h2>My IP address is: (.+)</h2>"
    MatchCollection matches1 = Regex.Matches(str, pattern);
    string ip = matches1(0).ToString;
    ip = ip.Remove(0, 21);
    ip = ip.Replace("

    ", "");
    ip = ip.Replace(" ", "");
    return IPAddress.Parse(ip);
}

Answer 6

private static string GetPublicIpAddress()
{
    using (var client = new WebClient())
    {
       return client.DownloadString("http://ifconfig.me").Replace("\n", "");
    }
}