/// <summary>
/// Performs an automated lookup at whatismyip.com to determine the external IP of the calling server
/// </summary>
/// <returns>A string with the external IP of the calling server</returns>
public static string WhatIsMyIP()
{
// LOOK FOR CACHED IP INFORMATION
Cache cache = HttpContextHelper.SafeGetCache();
if (cache != null && cache["WhatIsMyIP"] != null)
{
return((string)cache["WhatIsMyIP"]);
}
// TRY TO GET IP FROM WEBSERVICE
string response = string.Empty;
try
{
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create("http://www.whatismyip.com/automation/n09230945.asp");
httpWebRequest.Method = "GET";
using (StreamReader responseStream = new StreamReader(httpWebRequest.GetResponse().GetResponseStream(), System.Text.Encoding.UTF8))
{
response = responseStream.ReadToEnd();
responseStream.Close();
}
if (!Regex.IsMatch(response, @"^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$"))
{
response = string.Empty;
}
}
catch { }
// CACHE AND RETURN RESPONSE
if (cache != null)
{
cache.Add("WhatIsMyIP", response, null, Cache.NoAbsoluteExpiration, new TimeSpan(0, 10, 0), CacheItemPriority.Normal, null);
}
return(response);
}
