how to determine whether an IP address in private?

Question

So far I have this code:

NetworkInterface[] adapters = NetworkInterface.GetAllNetworkInterfaces();

foreach (NetworkInterface adapter in adapters)
{
  IPInte         


        

Answer 1

The private address ranges are defined in RFC1918. They are:

• 10.0.0.0 - 10.255.255.255 (10/8 prefix)
• 172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
• 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)

You might also want to filter out link-local addresses (169.254/16) as defined in RFC3927.