Big sur udp broadcast not working normally

Has anyone had trouble with udp broadcasting failing to receive/send out in Big Sur?

It seems 9/10 times udp broadcasting is suddenly failing since big sur. Perhaps anyone has suggestions?

The udp socket has no errors, isconnected (bound) shows true and the socket stays that way without notifying or getting an error.

For Big Sur you need to use the new Privacy Message for UDP packets and your app must be code signed with Hardened Runtime or the App Sandbox. I’ve already added support for the UDP messages in App Wrapper 4, on the Capabilities page, under the networking section.

You can give the public beta of AW4 a while at

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In some ways I’m beginning to hate Apple. They just eliminated functionality for a huge number of apps and devices. What if you have a hardware device that uses UDP for broadcasting messages.


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They’re just asking you to clarify why you need UDP and requiring you to sign & harden. Personally I’d rather have some constraints on these things because it’s far to easy to send data out without the user’s knowledge.


W’ve added the multicast entitlement and it seemed to be working better. Still not always as it was previously but it’s a start.

This has nothing to do with codesigning since you can still do everything locally (so says apple). So far i’ve added more polling. The user is asked to use the service (by our app) and the service(s) all run based on udp detection.

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