NetworkUtils

gistfile1.cs

using System;
using System.Security;
using System.Net;
using System.Net.Sockets;
namespace Demo
{
	public class NetworkUtils
	{
		/// <summary>
		/// Performs a hostname lookup from an IP.
		/// </summary>
		/// <param name="Ip"></param>
		/// <returns></returns>
		public static string GetHostnameFromIp(string Ip)
		{
			string hostname = "";
			try
			{
				IPHostEntry ipHostEntry = Dns.GetHostByAddress(Ip);
				hostname = ipHostEntry.HostName;
			}
			catch (FormatException)
			{
				hostname = "Please specify a valid IP address.";
				return hostname;
			}
			catch (SocketException)
			{
				hostname = "Unable to perform lookup - a socket error occured.";
				return hostname;
			}
			catch (SecurityException)
			{
				hostname = "Unable to perform lookup - permission denied.";
				return hostname;
			}
			catch (Exception)
			{
				hostname = "An unspecified error occured.";
				return hostname;
			}

			return hostname;
		}
		/// <summary>
		/// Performs an IP lookup from a hostname.
		/// </summary>
		/// <param name="Hostname"></param>
		/// <returns></returns>
		public static string GetIpFromHostname(string Hostname)
		{
			string ip = "";
			try
			{
				IPHostEntry ipHostEntry = Dns.Resolve(Hostname);
				if ( ipHostEntry.AddressList.Length > 0 )
				{
					//ip = ipHostEntry.AddressList[0].Address.ToString();
					ip = ipHostEntry.AddressList[0].ToString();
				}
				else
				{
					ip = "No information found.";
				}
			}
			catch ( SocketException )
			{
				ip = "Unable to perform lookup - a socket error occured.";
				return ip;
			}
			catch ( SecurityException )
			{
				ip = "Unable to perform lookup - permission denied.";
				return ip;
			}
			catch ( Exception )
			{
				ip = "An unspecified error occured.";
				return ip;
			}

			return ip;
		}
	}
}