Program.cs

using System;
using System.Threading.Tasks;
using DNS.Client;
using DNS.Server;

namespace captivateme
{
    class DNSClientServer
    {

        public const int PortDefault = 53535;
        public const string ReferenceDNSDefault = "1.1.1.1";
        public const string RedirectIPDefault = "127.0.0.1";


        public static void Main(string[] args)
        {
            MainAsync().Wait();
        }

        public async static Task MainAsync()
        {
            // Grab environment variables.
            string PortEnviron = Environment.GetEnvironmentVariable("PORT");
            string ReferenceDNSEnviron = Environment.GetEnvironmentVariable("REFERENCE_DNS");
            string RedirectIPEnviron = Environment.GetEnvironmentVariable("REDIRECT_IP");

            // Set the PORT.
            int Port;
            int.TryParse(PortEnviron, out Port);

            // Set Default port, if none was provided.
            if (Port == 0)
            {
                Port = PortDefault;
            }

            // Set variables for later use.
            string ReferenceDNS = ReferenceDNSEnviron ?? ReferenceDNSDefault;
            string RedirectIP = RedirectIPEnviron ?? RedirectIPDefault;

            // Create Zone file and DNS server instance.
            MasterFile masterFile = new MasterFile();
            DnsServer server = new DnsServer(masterFile, ReferenceDNS);

            // Intercept IP addresses.
            foreach (string domainPattern in new string[] {
                // TLDs.
                "*",
                // Domains
                "*.*",
                // Subdomains.
                "*.*.*"
            })
            {
                // Write IP Redirect to Zone file.
                masterFile.AddIPAddressResourceRecord(domainPattern, RedirectIP);
            }

            // Request hook:
            // server.Requested += (sender, e) => Console.WriteLine("Requested: {0}", e.Request);
            // Response hook:
            server.Responded += (sender, e) => Console.WriteLine("Responded: {0} => {1}", e.Request, e.Response);
            // Error hook:
            server.Errored += (sender, e) => Console.WriteLine("Errored: {0}", e.Exception.Message);
            // Listening (port open) hook:
            server.Listening += (sender, e) => Console.WriteLine("Listening on port {0}:", Port);

            // Test connection, to ensure things are working properly:
            server.Listening += async (sender, e) =>
            {
                DnsClient client = new DnsClient("127.0.0.1", Port);

                await client.Lookup("go.com");
            };

            await server.Listen(Port);
        }
    }
}

oh out?