Simple functions to manipulate UInt32 for use with ip addressing.

ip.cs

using System;

namespace ip
{
	class MainClass
	{
		public static void Main(string[] args)
		{
			//Console.WriteLine("Hello World!");

			unchecked
			{
				ulong ip = (UInt32)(192 << 24) + (168 << 16) + (1 << 8) + 10;
				Console.WriteLine(ip);

				string ips = (255 & (ip >> 24)) + "."
						   + (255 & (ip >> 16)) + "."
						   + (255 & (ip >> 8)) + "."
						   + (255 & ip);
				Console.WriteLine(ips);
			}

			Console.WriteLine(DDtoUInt("192.168.1.10"));

			Console.WriteLine(UIntToDD(DDtoUInt("192.168.1.10")));

			Console.WriteLine(CIFStoUint(16));
			Console.WriteLine(UIntToDD(CIFStoUint(8)));
			Console.WriteLine(UIntToDD(CIFStoUint(16)));
			Console.WriteLine(UIntToDD(CIFStoUint(24)));

			Console.WriteLine(UIntToBitPattern(DDtoUInt("192.168.1.10")));
			Console.WriteLine(UIntToBitPattern(Convert.ToUInt32(-10)));
			//Console.WriteLine(UIntToBitPattern(-10));


			Console.WriteLine(DDtoUInt("192.168.1.10.22"));

		}

		public static UInt32 DDtoUInt(string dd)
		{
			string[] ip_strings = dd.Split('.');
			if (ip_strings.Length != 4)
			{
				throw new FormatException("Forkert format i " + dd);
			}
			else
			{
				int[] ip_bytes = {
					Convert.ToByte(ip_strings[3]),
					Convert.ToByte(ip_strings[2]),
					Convert.ToByte(ip_strings[1]),
					Convert.ToByte(ip_strings[0])
				};

				unchecked
				{
					UInt32 ip = (UInt32)(ip_bytes[3] << 24)
							  + (UInt32)(ip_bytes[2] << 16)
							  + (UInt32)(ip_bytes[1] << 8)
							  + (UInt32)ip_bytes[0];
					return ip;
				}
			}
		}

		public static string UIntToDD(UInt32 ip)
		{ 
			string ips = (255 & (ip >> 24)) + "."
					   + (255 & (ip >> 16)) + "."
					   + (255 & (ip >> 8)) + "."
					   + (255 & ip);
			return ips;
		}

		public static UInt32 CIFStoUint(byte nBits)
		{
			unchecked
			{
				UInt32 ip = (UInt32)(~0);
				ip = ip << 32 - nBits;
				return ip;
			}
		}

		public static string UIntToBitPattern(UInt32 ip)
		{
			string result = "";
			for (int i = 31; i >= 0; i--)
			{
				result += 1 & (ip >> i);
			}
			return result;
		}

	}
}