Hey There. I'm working on a NEDNSProxyProvider for Mac. Most of it it working quite well, however we see the following events occurring regularly: our handleNewUDPFlow implementation gets called. as per the documentation, we retain the flow, and return true. We immediately open the flow by calling flow.open The open error callback occurs straight away with an Error "The peer closed the flow". I see this particularly when the initialRemoteEndpoint parameter to my handleNewUDP flow is off network. So, for example if my initialRemoteEndpoint is an IP address on my network (i.e. in the non-routable 192.168... network where by default DNS address is), the open works fine. However, I've noticed that a number of applications are making DNS requests aimed at "well known" DNS servers, so the initial endpoint contains a routable address. In this scenario, as soon as I open the flow, it closes with an error, and I can't honour the request.