Enumerating MS SQL Server instances in different ways

enumsqlservers.cs

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Text.RegularExpressions;
using Microsoft.SqlServer.Management.Smo;

namespace EnumSqlServers
{
	internal class Program
	{
		private static void Main()
		{
			try
			{
				// 1. Try library method

				var dataTable = SmoApplication.EnumAvailableSqlServers(false);

				if (dataTable.Rows.Count > 0)
				{
					foreach (DataRow row in dataTable.Rows)
					{
						Console.WriteLine("{0}", row["Name"]);
					}
				}

				// 2. Using sockets

				var socket = new Socket(AddressFamily.InterNetworkV6, SocketType.Dgram, ProtocolType.Udp)
				{
					EnableBroadcast = true,
					ReceiveTimeout = 1000,
					DualMode = true
				};

				var bytes = new List<byte>(4096);

				try
				{
					var ipv4ep = new IPEndPoint(IPAddress.Broadcast, 1434);
					var ipv6ep = new IPEndPoint(IPAddress.Parse("ff02::1"), 1434);
					byte[] msg = {0x02};
					socket.SendTo(msg, ipv4ep);
					socket.SendTo(msg, ipv6ep);

					int cnt = 0;
					byte[] byteBuffer = new byte[256];

					do
					{
						cnt = socket.Receive(byteBuffer);

						bytes.AddRange(byteBuffer.Take(cnt));

					} while (cnt != 0);
				}
				catch (SocketException sex)
				{
					const int WSAETIMEDOUT = 10060; // Connection timed out. 
					const int WSAEHOSTUNREACH = 10065; // No route to host. 

					if (sex.ErrorCode == WSAETIMEDOUT || sex.ErrorCode == WSAEHOSTUNREACH)
					{
					}
					else
					{
						throw;
					}
				}
				finally
				{
					socket.Close();
				}

				string text = Encoding.ASCII.GetString(bytes.ToArray());

				var servers = text.Split(new[] {";;"}, StringSplitOptions.RemoveEmptyEntries).Select(s => s.Substring(s.IndexOf("ServerName", StringComparison.Ordinal)));

				var regex = new Regex(@"^ServerName;(?<server>\w+);InstanceName;(?<instance>\w+);.*", RegexOptions.Compiled);

				Console.WriteLine();

				foreach (var server in servers)
				{
					// parse it with regex
					var match = regex.Match(server);
					Console.WriteLine("{0}\\{1}", match.Groups["server"], match.Groups["instance"]);
				}
			}
			catch (Exception ex)
			{
				Console.WriteLine(ex.Message);
			}
		}
	}
}