// the order is important, if we want to support bitwise OR: IPv4 | IPv6 equals IPv4and6
public enum IpVersion
{
    None,
    IPv4,
    IPv6,
    IPv4and6
}

public async Task<IpVersion> GetCurrentIpVersion()
{
    try
    {
        // resolves domain name to IP addresses (may contain several)
        var endPointPairs = await DatagramSocket.GetEndpointPairsAsync(new HostName("google.com"), "0");
        if (endPointPairs == null)
        {
            return IpVersion.None;
        }

        var result = IpVersion.None;
        foreach (var endPoint in endPointPairs)
        {
            if (endPoint.RemoteHostName != null && (endPoint.RemoteHostName.Type == HostNameType.Ipv4 || endPoint.RemoteHostName.Type == HostNameType.Ipv6))
            {
                result |= (endPoint.RemoteHostName.Type == HostNameType.Ipv4 ? IpVersion.IPv4 : IpVersion.IPv6);
            }
        }
        return result;
    }
    catch
    {
        return IpVersion.None;
    }
}