Question

When I open firefox and enter “209.191.122.70” as the URL and press enter, it immediately resolves to “http://failsafe.fp.yahoo.com/404.html”

My goal is to retrieve the same information programmatically.

When I use the following code, either I end up with a SocketException or I end up with a HostName that doesn’t look like the url I get when I use firefox.

    static void Main(string[] args)
    {
        IPHostEntry entry = Dns.GetHostByAddress("209.191.122.70");
        Console.WriteLine(entry.HostName); //ir1.fp.vip.mud.yahoo.com
        Console.Read();
    }

The System.Net.Sockets.SocketException I get when I try some other addresses says “The requested name is valid, but no data of the requested type was found” and the stack trace looks as follows:

 at System.Net.Dns.InternalGetHostByAddress(IPAddress address, Boolean includeIPv6, Boolean throwOnFailure)
 at System.Net.Dns.GetHostByAddress(String address)
 at reverseIP.Program.Main(String[] args) in C:\test\Program.cs:line 15

Some of the addresses that give me exceptions resolve fine in firefox.

Other than starting Firefox as a separate process and retrieving the text in the address bar using the Windows API, how can I retrieve the information I’m looking for?

Answer 1

The System.Windows.Forms.WebBrowser class helped me obtain the info I was looking for.