How to determine if a string is a valid IPv4 or IPv6 address in C#?

Question

I know regex is dangerous for validating IP addresses because of the different forms an IP address can take.

I've seen similar questions for C and C++, and those were resolved with a function that doesn't exist in C# inet_ntop()

The .NET solutions I've found only handle the standard "ddd.ddd.ddd.ddd" form. Any suggestions?

Answer 1

You can use this to try and parse it:

 IPAddress.TryParse 

Then check AddressFamily which

Returns System.Net.Sockets.AddressFamily.InterNetwork for IPv4 or System.Net.Sockets.AddressFamily.InterNetworkV6 for IPv6.

EDIT: some sample code. change as desired:

    string input = "your IP address goes here";      IPAddress address;     if (IPAddress.TryParse(input, out address))     {         switch (address.AddressFamily)         {             case System.Net.Sockets.AddressFamily.InterNetwork:                 // we have IPv4                 break;             case System.Net.Sockets.AddressFamily.InterNetworkV6:                 // we have IPv6                 break;             default:                 // umm... yeah... I'm going to need to take your red packet and...                 break;         }     }