How to check if an IP address is within a particular subnet
Take a look at IP Address Calculations with C# on MSDN blogs. It contains an extension method (IsInSameSubnet) that should meet your needs as well as some other goodies. public static class IPAddressExtensions { public static IPAddress GetBroadcastAddress(this IPAddress address, IPAddress subnetMask) { byte[] ipAdressBytes = address.GetAddressBytes(); byte[] subnetMaskBytes = subnetMask.GetAddressBytes(); if (ipAdressBytes.Length != subnetMaskBytes.Length) … Read more