Recently, my application was having trouble sending udp messages after it was reinstalled. The cause of the problem was initially that I did not grant local network permissions when I reinstalled, I was aware of the problem, so udp worked fine after I granted permissions. However, the next time I repeat the previous operation, I also do not grant local network permissions, and then turn it back on in the Settings, and udp does not work properly (no messages can be sent, the system version and code have not changed). Fortunately, udp worked after rebooting the phone, and more importantly, I was able to repeat the problem many times. So I want to know if the process between when I re-uninstall the app and deny local network permissions, and when I turn it back on in Settings, is that permissions have been granted normally, and not fake, and not required a reboot to reset something for udp to take effect. I'm not sure if it's the system, or if it's a similar situation as described here, hopefully that will help me find out
My experience is there are two causes of problems like this. The first is covered by FAQ-16 in the Local Network Privacy FAQ. However, such problems are persistent; restarting your device doesn’t fix the issue. You wrote:
Fortunately, udp worked after rebooting the phone …
which means we’re looking at something else.
My general opinion is that, if restarting fixes an LNP problem, that’s a bug in iOS itself. If you’re able to reproduce this, even if only intermittently, I encourage you to file a bug about it. Make sure to include a sysdiagnose log taken shortly after reproducing the problem and before you restart. That’s going to be critical to the analysis. Oh, and if you’re willing to leave that device with the Network Diagnostics for iOS debug profile installed — see our Bug Reporting > Profiles and Logs page — that’d be ideal.
If you do file a bug, please post your bug number, just for the record.
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"