Access Denied

[vbisbest]

I am getting some users with "Access Denied" error on ConnectAsync. I cannot repro the issue and I have no idea whats causing it. It seems the things in common are that they are using iPhone 6s, and on T-Mobile Cellular. Scrrenshot attached of the error.

[rdavisau]

Howdy.. haven't come across an error like this before. Remind me, are you using TCP or UDP sockets?

Does your application open many socket connections over time?

[vbisbest]

TCP. And yes, opens around 10-12 sockets all at the same time. Each on their on thread.

[vbisbest]

I think I found the issue. It appears that I am opening with an IPV6 address (not intended on my part!). I assume your libarary does not work with IPv6?

[rdavisau]

Interesting - I don't do anything to explicitly support or not support ipv6 - but I've had people in the past discuss adding support for it. No idea how big of a change it is the API and not enough bandwidth to explore it at the moment.. I was hoping it might 'just work', but it looks like that's not the case!

[WilhelmJP]

Hello David,

My app was rejected by app store because it does not work via IPv6 Wi-fi. On IPv4 Wi-Fi all works perfect. Therefor, I have setup an IPv6 Wi-Fi network using my mac as described here:

https://developer.apple.com/library/content/documentation/NetworkingInternetWeb/Conceptual/NetworkingOverview/UnderstandingandPreparingfortheIPv6Transition/UnderstandingandPreparingfortheIPv6Transition.html

The app makes a discovery to get knx interfaces (knx is a standard for building automation (knx.org)) available on a LAN.

Get all interfaces works: var networkInterface = CommsInterface.GetAllInterfacesAsync().Result.FirstOrDefault(_ => _.IpAddress == ipv4.ToString()); Join works: udpClient.JoinMulticastGroupAsync( RoutingConnector.DefaultMulticastAddress.ToString(), RoutingConnector.DefaultPort, networkInterface).Wait();

But the call

            var sendTask = udpClient.SendMulticastAsync(searchRequest);
            sendTask.Wait();

Throws the exception Exception in Connect: System.AggregateException: One or more errors occurred. ---> System.Net.Sockets.SocketException: No route to host at System.Net.Sockets.Socket.EndSend (IAsyncResult result) [0x0002d] in /Users/builder/data/lanes/3539/f37444ae/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/mcs/class/System/System.Net.Sockets/Socket.cs:2648

I assume the problem could be that the UdpClient uses the IPv4 address from the networkInterace object and has to use the IPv6 mapped address.

Best regards Wilhelm