IPv6 - Apple rejects iOS app because of not Supporting IPv6 DNS64 / NAT64 Networks

Question

Where is the error?

Apple reject app and sent messege:

Performance - 2.1

We discovered one or more bugs in your app when reviewed on iPad and iPhone running iOS 9.3.5 on Wi-Fi connected to an IPv6 network.

Specifically, an error is displayed when a vote is made and Supporting IPv6 DNS64 / NAT64 Networks

"If you’re writing a client-side app using high-level networking APIs such as NSURLSession and the CFNetwork frameworks and you connect by name, you should not need to change anything for your app to work with IPv6 addresses."

Next on Apple Developer Forums says:

N 3 — Will I need to update my server? That depends on where your server is running: If you have a server running on the wider Internet, the answer is no. Your server will be accessible to IPv6-only devices via DNS64/NAT64. You should update your server to support IPv6 as a matter of course, but that’s something you can do in your own time. If you have a server embedded within your iOS app (for example, a web server that allows users to transfer files to and from your app), you should make sure it works well in an IPv6-only environment.

My hoster says:

We do not see any problems, for the server with IPv6 to your server is IPv4 will be available through DNAT / SNAT

My site (server): http://badroads.info

My code in App (this code was approved in another application a week ago):

func sendToServer(dataFromDictionary: Dictionary<NSString, AnyObject>) {
    let url: NSURL = NSURL(string: "http://badroads.info/t-or-c/****.php")!
    let request:NSMutableURLRequest = NSMutableURLRequest(URL:url)
    let session = NSURLSession.sharedSession()
    request.HTTPMethod = "POST"
    do {
        request.HTTPBody = try NSJSONSerialization.dataWithJSONObject(dataFromDictionary, options: [])
    } catch let parseError as NSError {
        request.HTTPBody = nil
        dispatch_async(dispatch_get_main_queue()) {
            EZLoadingActivity.hide()
            
            self.alertMessageSuccessError("Error", messageM: "Oops, something went wrong! Try again, please!")
        }
    }
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")
    let task = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
        if error != nil {
            dispatch_async(dispatch_get_main_queue()) {
                EZLoadingActivity.hide()
                self.alertMessageSuccessError("Error", messageM: "Oops, something went wrong! Try again, please!")
            }
            return
        }
        let json: NSDictionary?
        do {
            json = try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableLeaves) as? NSDictionary
        } catch let parseError as NSError {
            dispatch_async(dispatch_get_main_queue()) {
                EZLoadingActivity.hide()
                self.alertMessageSuccessError("Error", messageM: "Oops, something went wrong! Try again, please!")
            }
            return
        }
        if let parseJSON = json {
            if let status = parseJSON["status"] as? String {
                if status == "200" {
                    dispatch_async(dispatch_get_main_queue()) {
                        EZLoadingActivity.hide()
                        self.defaultsDataLogin.setObject(true, forKey: "isDone")
                        self.alertMessageAdM("Successfully!", messageM: "See  results!")
                    }
                } else if status == "400" {
                    dispatch_async(dispatch_get_main_queue()) {
                        EZLoadingActivity.hide()
                        self.alertMessageSuccessErrorAdM("Error", messageM: "You have already data!")
                    }
                } else {
                    dispatch_async(dispatch_get_main_queue()) {
                        EZLoadingActivity.hide()
                        self.alertMessageSuccessError("Error", messageM: "Oops, something went wrong! Try again, please!")
                    }
                }
            } else {
                dispatch_async(dispatch_get_main_queue()) {
                    EZLoadingActivity.hide()
                    self.alertMessageSuccessError("Error", messageM: "Oops, something went wrong! Try again, please!")
                }
            }
            
        }  else {
            dispatch_async(dispatch_get_main_queue()) {
                EZLoadingActivity.hide()
                self.alertMessageSuccessError("Error", messageM: "Oops, something went wrong! Try again, please!")
            }
        }
    })
    task.resume()
}

But I checked my site on https://ip6.nl and http://ipv6-test.com/validate.php I got the following results:

Thanks!

Answer 1

It is not about your server.

There must be few APIs in your application which are not supported to IPV6 (e.g. Reachability). Please update those with the latest and IPV6 supported ones.

I think NAT64 is not so much helpful.

Answer 2

It doesn't have to be an IPv6 network support issue. The app crashes and it is connected to an IPv6 network. It can be two different things. Ask the review team for crash logs, symbolicate those logs and find out whats the real problem.