IP Address Returning Question

[Fuzz13]

I am using a Ping member to ping a website from 2 different computers. The first computer is the websites server where all the files etc for the website are stored. The second computer running the test is a computer not hosting those files, so any computer not the server.

Here is my code:

string website = "www.somesite.com";
            Ping ping = new Ping();
            PingReply reply = ping.Send(website);
            if (reply.Status == IPStatus.Success)
            {
                rtxtbxDemo.Text = ("Address: " + reply.Address.ToString());
            }
 

The problem I am running into is that on the computer that is not the server the returned ip address is correct and reflects that websites dynamic IP address. When I run the app from the server it returns what I can only assume is the local IP address?
Request 1 (non server): 174.23.226.240
Request 2 (server): 127.0.0.2

I need the ip address that is returned by the non server computer however I need to run the program on the actual sever computer. What IP address am I most likely having returned when pinging the site on the server computer itself and how do I send a request for the websites IP like is being returned in request 1?

[Curtis Rutland]

This is really a network type question. The server doesn't know it's own external IP address. That's something a router handles. The DNS resolution to the URL is local, so it pings the local address.

You'd need to find out the external address of this web server, and ping that IP rather than the URL itself.

If you were looking to programatically obtain a machine's IP address, you could use WhatIsMyIp.com's Automation page. Read more about that here.

[Fuzz13]

So when I ping the site from the non sever computer it returns an IP address from that servers router, but when the server itself tries to ping the site it gathers its local IP not what is returned via the router. So in order to get the same returned IP address from the server I need to have something like WhatIsMyIp.com to send the request back at my server so it can tell me what it gets returned from the router as the IP address, correct?

When I use the Ping member it returns the Address in a very clean use-able variable. When I use the whatsmyip.com/automation I assume I will have to do some formatting to clean up any kind of returned data so I have just the needed IP address returned?

[Curtis Rutland]

That page should just respond with a string. No HTML, nothing except for the characters of your IP address. You could split them around '.' and make an IP out of it.

[Fuzz13]

My last question on that is the program would need to ping that website "http://www.whatismyip.com/automation/n09230945.asp" which would tell the website to send its own request back at the requesting computers router which then would have the website display the returned IP address? So my code needs to instead send its ping request at the mentioned url rather then the website I would want to monitor from an outside computer?

ex. Outside computer sends ping request at: www.mywebsite.com returns ip address for that site.
Server computer sends ping request at: http://www.whatismyip.com/automation/n09230945.asp which then thru formatting would have a returned string of the ip address.

Does that sound accurate?

[Fuzz13]

I am becoming confused why my ping is not correct though? When I send a ping from any computer it should go to that url and return that url's IP address right? Why would that be different on the server? The server should be sending pinging the url as well which would then return the IP address?

[Plater]

To answer that last question, you would need a better understanding of networking.

For using the automation page:
All you would do is populate an IPAddress object (do some from your server computer's code) with the page's result text and you will have your server's outside IPaddress. Try using HttpWebRequest. They should create the same IP as the Ping command you used on other computers.
You would NOT use the ping command on the whatsmyIP automation page.

[Fuzz13]

I'm having some issues understanding how to return the string from whatsmyipaddress's automation page. I can't seem to figure out what method I call using the HttpWebResponse. I've got:

 HttpWebRequest myHttpWebRequest = (HttpWebRequest)WebRequest.Create("http://www.whatismyip.com/automation/n09230945.asp");
            HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();
 
            rtxtbxDemo.Text = myHttpWebResponse.ToString();
 

MSDN is not helping me very much on this as I can't understand what they are doing in their examples. What would I need to use to call the returned data from that site, meaning the string it lists?

[Fuzz13]

I found a great little example that did exactly what I needed. This is the code:

 // used to build entire input
            StringBuilder sb = new StringBuilder();
 
            // used on each read operation
            byte[] buf = new byte[8192];
 
            // prepare the web page we will be asking for
            HttpWebRequest request = (HttpWebRequest)
                WebRequest.Create("http://www.whatismyip.com/automation/n09230945.asp");
 
            // execute the request
            HttpWebResponse response = (HttpWebResponse)
                request.GetResponse();
 
            // we will read data via the response stream
            Stream resStream = response.GetResponseStream();
 
            string tempString = null;
            int count = 0;
 
            do
            {
                // fill the buffer with data
                count = resStream.Read(buf, 0, buf.Length);
 
                // make sure we read some data
                if (count != 0)
                {
                    // translate from bytes to ASCII text
                    tempString = Encoding.ASCII.GetString(buf, 0, count);
 
                    // continue building the string
                    sb.Append(tempString);
                }
            }
            while (count > 0); // any more data to read?
 
            // print out page source
             rtxtbxDemo.Text = sb.ToString();
 

I am populating the returned websites data into a richtext box here.

I think this will do what I need. I hope it helps someone else as well.

[Plater]

The manor in which the bytes from the response stream are read back is a bit messy, but yes, that is pretty much what we were suggesting.

[Fuzz13]

Plater: I am entirely open to suggestions that cleans up the code. As I mentioned I got it from an example and I only know it returns what I need. I have been going thru it piece by piece as I do not understand it thoroughly.

[Plater]

Modified:

public static string GetIpAddress()
{
  string retval = "";
  try
  {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://www.whatismyip.com/automation/n09230945.asp");
        // execute the request 
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        StreamReader sr = new StreamReader(response.GetResponseStream());
        retval=sr.ReadLine();
  }
  catch (Exception ee)
  {//do failure logic here
  }
  return retval;
}
 

Then you can say:
rtxtbxDemo.Text =GetIpAddress();