Force HttpWebRequest to IPv4

Here’s how you can enforce the usage of IPv4 in Dual Stack environments with HttpWebRequests in C#/.NET:

string host = @"www.peschuster.de";
IPHostEntry ipHostEntry = Dns.GetHostEntry(host);
IPAddress address = ipHostEntry.AddressList.FirstOrDefault(a => a.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
    ?? ipHostEntry.AddressList.FirstOrDefault();
                
var request = HttpWebRequest.Create("http://" + address.ToString() + "/2016/04/force-httpwebrequest-to-ipv4") as HttpWebRequest;
request.Host = host;

request.GetResponse();

This is a very basic example. You should add some checks, whether the address could actually be resovled, etc. for use in production.