using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
//DnsLookup
class Program {
    static void Output(IPHostEntry ipHostEntry) {
        Console.WriteLine("Host: {0}", ipHostEntry.HostName);
        Console.WriteLine("
Aliases:");
        foreach (string alias in ipHostEntry.Aliases) {
            Console.WriteLine(alias);
        }

        Console.WriteLine("
Address(es):");
        foreach (IPAddress address in ipHostEntry.AddressList) {
            Console.WriteLine("Address: {0}", address.ToString());
        }
        Console.ReadLine();
    }

    static void Lookup(string hostname) {
        IPHostEntry ipHostEntry = Dns.GetHostByName(hostname);

        Output(ipHostEntry);
    }

    static void ReverseLookup(string address) {
        IPHostEntry ipHostEntry = Dns.GetHostByAddress(address);
        Output(ipHostEntry);
    }

    static void Main(string[] args) {


        Lookup("www.microsoft.com");
        ReverseLookup("172.18.1.1");
    }

}