You should contact that developer, but they are probably testing it.

Do you mean "now" creating a Network System Extension? I did actually look at the console log. As it happens I opened a TSI because money is no object and I have a few lying around for free anyway. If we solve it for general we could post it here. Thanks for the information on the os_log. Is that also visible in the Console.app in the Devices streaming part?

you should test yourself via TestFlight, running using Xcode isn't a valid way to test.

meaton you mentioned that NEDNSProxyProvider needs to be supervised on iOS, Is that not the case on macOS? Also, I think you mentioned some time ago that there was some documents forthcoming on this.

Thanks Matt. I was aware of ifconfig and aware that there are three utun* interfaces running by default on Big Sur. Most seem to be Apple related. scutil --nc list  doesn't seem to return anything for two VPNS I have tried, TunnelBlick and Viscosity. I get: Available network connection services in the current set (*=enabled): and then nothing. for now I am making the assumption that Apple services using the utun interfaces are ip6 and most VPNS are on ip4 so I test for           "State:/Network/Interface/utun\(n)/IPv4" I listen on: State:/Network/Global/IPv4, which seems to work for all cases of network or interface changes However I am stuck as how to recognise a ip6 VPN. I can surely catch a new iP6 but it might be an additional Apple service. There's no way, as far as I can see, to differentiate between an Apple service running on the network interface and third party services.