Local Network Privacy FAQ

IMPORTANT This FAQ has been replaced by TN3179 Understanding local network privacy. I’m leaving this post in place as a historical curiosity, but please consult the technote going forward.

I regularly get asked questions about local network privacy. This is my attempt to collect together the answers for the benefit of all. Before you delve into the details, familiarise yourself with the basics by watching WWDC 2020 Session 10110 Support local network privacy in your app.

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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
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Local Network Privacy FAQ

With local network privacy, any app that wants to interact with devices on your network must ask for permission the first time that it attempts that access. Local network privacy is implemented on iOS, iPadOS, visionOS, and macOS. It’s not implemented on other platforms, most notably tvOS.

IMPORTANT macOS 15 (currently in beta) introduced local network privacy support to the Mac. WWDC 2024 Session 10123 What’s new in privacy is the official announcement. This works much like it does on iOS, but there are some subtle differences. I’ll update this FAQ as I gain more experience with this change.

Some common questions about local network privacy are:

• FAQ-1 What is a local network?

• FAQ-2 What operations require local network access?

• FAQ-3 What operations require the multicast entitlement?

• FAQ-4 Do I need the multicast entitlement?

• FAQ-5 I’ve been granted the multicast entitlement; how do I enable it?

• FAQ-6 Can App Clips access the local network?

• FAQ-7 How does local network privacy work with app extensions?

• FAQ-8 How do I explicitly trigger the local network privacy alert?

• FAQ-9 How do I tell whether I’ve been granted local network access?

• FAQ-10 How do I use the unsatisfied reason property?

• FAQ-11 Do I need a local network usage description property?

• FAQ-12 Can I test on the simulator?

• FAQ-13 Once my app has displayed the local network privacy alert, how can I reset its state so that it shows again?

• FAQ-14 How do I map my Multipeer Connectivity service type to an entry in the Bonjour services property?

• FAQ-15 My app presents the local network privacy alert unexpectedly. Is there a way to track down the cause?

• FAQ-16 On a small fraction of devices my app fails to present the local network privacy alert. What’s going on?

• FAQ-17 Why does local network privacy get confused when I install two variants of my app?

• FAQ-18 Can my app trigger the local network privacy alert when the device is on WWAN?

Revision History

• 2024-10-31 Added a link to this FAQ’s replacement, TN3179 Understanding local network privacy.

• 2024-07-22 Added a callout explaining that local network privacy is now an issue on macOS.

• 2023-10-31 Fixed a bug in the top-level FAQ that mistakenly removed some recent changes. Added FAQ-18.

• 2023-10-19 Added a preamble to clarify that local network privacy is only relevant on specific platforms.

• 2023-09-14 Added FAQ-17.

• 2023-08-29 Added FAQ-16.

• 2023-03-13 Added connecting a UDP socket to FAQ-2.

• 2022-10-04 Added screen shots to FAQ-11.

• 2022-09-22 Fixed the pointer from FAQ-9 to FAQ-10.

• 2022-09-19 Updated FAQ-3 to cover iOS 16 changes. Made other minor editorial changes.

• 2020-11-12 Made a minor tweak to FAQ-9.

• 2020-10-17 Added FAQ-15. Added a second suggestion to FAQ-13.

• 2020-10-16 First posted.