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Explore the networking protocols and technologies used by the device to connect to Wi-Fi networks, Bluetooth devices, and cellular data services.

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macOS Tahoe: IPMonitor incorrectly re-ranks interfaces causing VPN DNS leaks
Description Enterprise users are experiencing VPN resource access failures after upgrading to macOS Tahoe. Investigation indicates that configd (specifically IPMonitor) is incorrectly re-ranking network interfaces after a connectivity failure with probe server. This results in DNS queries routing through the physical network adapter (en0) instead of the VPN virtual adapter, even while the tunnel is active. This behaviour is not seen in previous macOS versions. Steps to Reproduce: Connect to an enterprise VPN (e.g., Ivanti Secure Access). Trigger a transient network condition where the Apple probe server is unreachable. For example make the DNS server down for 30 sec. Observe the system routing DNS queries for internal resources to the physical adapter. Expected Results The: VPN virtual interface should maintain its primary rank for enterprise DNS queries regardless of the physical adapter's probe status. Actual Results: IPMonitor detects an UplinkIssue, deprioritizes the VPN interface, and elevates the physical adapter to a higher priority rank. Technical Root Cause & Logs: The system logs show IPMonitor identifying an issue and modifying the interface priority at 16:03:54: IPMonitor Detection: The process identifies an inability to reach the Apple probe server and marks en0 with an advisory: Log snippet 2026-01-06 16:03:53.956399+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] configd[594] SetInterfaceAdvisory(en0) = UplinkIssue (2) reason='unable to reach probe server' Interface Re-ranking: Immediately following, IPMonitor recalculates the rank, placing the physical service ID at a higher priority (lower numerical rank) than the VPN service ID (net.pulsesecure...): Log snippet 2026-01-06 16:03:53.967935+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] 0. en0 serviceID=50CD9266-B097-4664-BFE6-7BAFCC5E9DC0 addr=192.168.0.128 rank=0x200000d 2026-01-06 16:03:53.967947+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] 1. en0 serviceID=net.pulsesecure.pulse.nc.main addr=192.168.0.128 rank=0x2ffffff 3.Physical adapter Is selected as Primary Interface: 2026-01-06 16:03:53.968145+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] 50CD9266-B097-4664-BFE6-7BAFCC5E9DC0 is the new primary IPv4 configd[594]: 50CD9266-B097-4664-BFE6-7BAFCC5E9DC0 is the new primary DNS Packet Trace Evidence Wireshark confirms that DNS queries for enterprise-specific DNS servers are being originated from the physical IP (192.168.0.128) instead of the virtual adapter: Time: 16:03:54.084 Source: 192.168.0.128 (Physical Adapter) Destination: 172.29.155.115 (Internal VPN DNS Server) Result: Connectivity Failure (Queries sent outside the tunnel)
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When updating a VPN app with `includeAllNetworks`, the newer instance of the packet tunnel is not started via on-demand rules
When installing a new version the app while a tunnel is connected, seemingly the old packet tunnel process gets stopped but the new one does not come back up. Reportedly, a path monitor is reporting that the device has no connectivity. Is this the expected behavior? When installing an update from TestFlight or the App store, the packet tunnel instance from the old tunnel is stopped, but, due to the profile being on-demand and incldueAllNetworks, the path monitoring believes the device has no connectivity - so the new app is never downloaded. Is this the expected behavior? During development, the old packet tunnel gets stopped, the new app is installed, but the new packet tunnel is never started. To start it, the user has to toggle the VPN twice from the Settings app. The tunnel could be started from the VPN app too, if we chose to not take the path monitor into account, but then the user still needs to attempt to start the tunnel twice - it only works on the second try. As far as we can tell, the first time around, the packet tunnel never gets started, the app receives an update about NEVPNStatus being set to disconnecting yet NEVPNConnection does not throw. The behavior I was naively expecting was that the packet tunnel process would be stopped only when the new app is fully downloaded and when the update is installed, Are we doing something horribly wrong here?
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Jan ’26
AccessorySetupKit – WiFi picker – show accessories after factory reset?
Hi there, We’re developing a companion app for a smart home product that communicates over the user’s local network. To provision the device, it initially creates its own Wi-Fi network. The user joins this temporary network and enters their home Wi-Fi credentials via our app. The app then sends those credentials directly to the device, which stores them and connects to the local network for normal operation. We’re using AccessorySetupKit to discover nearby devices (via SSID prefix) and NEHotspotManager to join the accessory’s Wi-Fi network once the user selects it. This workflow works well in general. However, we’ve encountered a problem: if the user factory-resets the accessory, or needs to restart setup (for example, after entering the wrong Wi-Fi password), the device no longer appears in the accessory picker. In iOS 18, we were able to work around this by calling removeAccessory() after the device is selected. This forces the picker to always display the accessory again. But in iOS 26, a new confirmation dialog now appears when calling removeAccessory(), which confuses users during setup. We’re looking for a cleaner way to handle this scenario — ideally a way to make the accessory rediscoverable without prompting the user to confirm removal. Thanks for your time and guidance.
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Nov ’25
Disable URLSession auto retry policy
We are developing an iOS application that is interacting with HTTP APIs that requires us to put a unique UUID (a nonce) as an header on every request (obviously there's more than that, but that's irrilevant to the question here). If the same nonce is sent on two subsequent requests the server returns a 412 error. We should avoid generating this kind of errors as, if repeated, they may be flagged as a malicious activity by the HTTP APIs. We are using URLSession.shared.dataTaskPublisher(for: request) to call the HTTP APIs with request being generated with the unique nonce as an header. On our field tests we are seeing a few cases of the same HTTP request (same nonce) being repeated a few seconds on after the other. Our code has some retry logic only on 401 errors, but that involves a token refresh, and this is not what we are seeing from logs. We were able to replicate this behaviour on our own device using Network Link Conditioner with very bad performance, with XCode's Network inspector attached we can be certain that two HTTP requests with identical headers are actually made automatically, the first request has an "End Reason" of "Retry", the second is "Success" with Status 412. Our questions are: can we disable this behaviour? can we provide a new request for the retry (so that we can update headers)? Thanks, Francesco
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Aug ’25
iOS 26 Network Framework AWDL not working
Hello, I have an app that is using iOS 26 Network Framework APIs. It is using QUIC, TLS 1.3 and Bonjour. For TLS I am using a PKCS#12 identity. All works well and as expected if the devices (iPhone with no cellular, iPhone with cellular, and iPad no cellular) are all on the same wifi network. If I turn off my router (ie no more wifi network) and leave on the wifi toggle on the iOS devices - only the non cellular iPhone and iPad are able to discovery and connect to each other. My iPhone with cellular is not able to. By sharing my logs with Cursor AI it was determined that the connection between the two problematic peers (iPad with no cellular and iPhone with cellular) never even makes it to the TLS step because I never see the logs where I print out the certs I compare. I tried doing "builder.requiredInterfaceType(.wifi)" but doing that blocked the two non cellular devices from working. I also tried "builder.prohibitedInterfaceTypes([.cellular])" but that also did not work. Is AWDL on it's way out? Should I focus my energy on Wi-Fi Aware? Regards, Captadoh
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Xcode 16.4 and above build error with Network Extension and WireGuard library
I have added a Network Extension to my iOS project to use the WireGuard library. Everything was working fine up to Xcode 16, but after updating, I’m facing a build issue. The build fails with the following error: No such file or directory: '@rpath/WireGuardNetworkExtensioniOS.debug.dylib' I haven’t explicitly added any .dylib to my project. The Network Extension target builds and runs fine on Xcode 16.
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Sep ’25
NEAppProxyUDPFlow.writeDatagrams fails with "The datagram was too large" on macOS 15.x, macOS 26.x
I'm implementing a NEDNSProxyProvider on macOS 15.x and macOS 26.x. The flow works correctly up to the last step — returning the DNS response to the client via writeDatagrams. Environment: macOS 15.x, 26.x Xcode 26.x NEDNSProxyProvider with NEAppProxyUDPFlow What I'm doing: override func handleNewFlow(_ flow: NEAppProxyFlow) -> Bool { guard let udpFlow = flow as? NEAppProxyUDPFlow else { return false } udpFlow.readDatagrams { datagrams, endpoints, error in // 1. Read DNS request from client // 2. Forward to upstream DNS server via TCP // 3. Receive response from upstream // 4. Try to return response to client: udpFlow.writeDatagrams([responseData], sentBy: [endpoints.first!]) { error in // Always fails: "The datagram was too large" // responseData is 50-200 bytes — well within UDP limits } } return true } Investigation: I added logging to check the type of endpoints.first : // On macOS 15.0 and 26.3.1: // type(of: endpoints.first) → NWAddressEndpoint // Not NWHostEndpoint as expected On both macOS 15.4 and 26.3.1, readDatagrams returns [NWEndpoint] where each endpoint appears to be NWAddressEndpoint — a type that is not publicly documented. When I try to create NWHostEndpoint manually from hostname and port, and pass it to writeDatagrams, the error "The datagram was too large" still occurs in some cases. Questions: What is the correct endpoint type to pass to writeDatagrams on macOS 15.x, 26.x? Should we pass the exact same NWEndpoint objects returned by readDatagrams, or create new ones? NWEndpoint, NWHostEndpoint, and writeDatagrams are all deprecated in macOS 15. Is there a replacement API for NEAppProxyUDPFlow that works with nw_endpoint_t from the Network framework? Is the error "The datagram was too large" actually about the endpoint type rather than the data size? Any guidance would be appreciated. :-))
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Apr ’26
Network System Extension cannot use network interface of another VPN
Hi, Our project is a MacOS SwiftUI GUI application that bundles a (Sandboxed) System Network Extension, signed with a Developer ID certificate for distribution outside of the app store. The system network extension is used to write a packet tunnel provider (NEPacketTunnelProvider), as our project requires the creation of a TUN device. In order for our System VPN to function, it must reach out to a (self-hosted) server (i.e. to discover a list of peers). Being self-hosted, this server is typically not accessible via the public web, and may only be accessible from within a VPN (such as those also implemented using NEPacketTunnelProvider, e.g. Tailscale, Cloudflare WARP). What we've discovered is that the networking code of the System Network Extension process does not attempt to use the other VPN network interfaces (utunX) on the system. In practice, this means requests to IPs and hostnames that should be routed to those interfaces time out. Identical requests made outside of the Network System Extension process use those interfaces and succeed. The simplest example is where we create a URLSession.downloadTask for a resource on the server. A more complicated example is where we execute a Go .dylib that continues to communicate with that server. Both types of requests time out. Two noteworthy logs appear when packets fail to send, both from the kernel 'process': cfil_hash_entry_log:6088 <CFIL: Error: sosend_reinject() failed>: [30685 com.coder.Coder-Desktop.VPN] <UDP(17) out so b795d11aca7c26bf 57728068503033955 57728068503033955 age 0> lport 3001 fport 3001 laddr 100.108.7.40 faddr 100.112.177.88 hash 58B15863 cfil_service_inject_queue:4472 CFIL: sosend() failed 49 I also wrote some test code that probes using a UDP NWConnection and NWPath availableInterfaces. When run from the GUI App, multiple interfaces are returned, including the one that routes the address, utun5. When ran from within the sysex, only en0 is returned. I understand routing a VPN through another is unconventional, but we unfortunately do need this functionality one way or another. Is there any way to modify which interfaces are exposed to the sysex? Additionally, are these limitations of networking within a Network System Extension documented anywhere? Do you have any ideas why this specific limitation might exist?
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Jul ’25
Wi-Fi Aware Sample doesn't build in Xcode 26.0 beta
Hello, I'm trying to build the sample app from Building peer-to-peer apps that demonstrates Wi-Fi Aware. Upon downloading the example source code, opening it in Xcode 26.0 beta, and building the app, the compiler fails with: DeviceDiscoveryPairingView.swift:8:8 No such module 'DeviceDiscoveryUI' Is this a known issue? I know that DeviceDiscoveryUI was previously only a tvOS capability. Thanks
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Jun ’25
XPC doesn't work with network extension on app upgrade
Our app has a network extension (as I've mentioned lots 😄). We do an upgrade by downloading the new package, stopping & removing all of our components except for the network extension, and then installing the new package, which then loads a LaunchAgent causing the containing app to run. (The only difference between a new install and upgrade is the old extension is left running, but not having anything to tell it what to do, just logs and continues.) On some (but not all) upgrades... nothing ends up able to communicate via XPC with the Network Extension. My simplest cli program to talk to it gets Could not create proxy: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named blah was invalidated: failed at lookup with error 3 - No such process." UserInfo={NSDebugDescription=The connection to service named bla was invalidated: failed at lookup with error 3 - No such process.} Could not communicate with blah Restarting the extension by doing a kill -9 doesn't fix it; neither does restarting the control daemon. The only solution we've come across so far is rebooting. I filed FB11086599 about this, but has anyone thoughts about this?
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Is it allowed for a third-party iOS app to query time.apple.com (NTP/SNTP)? Any official usage guidance / rate limits?
I’m developing an iOS idle game (guild management). To detect manual device time changes that would break progression, I need a trusted “current real-world time” reference. I’m considering querying Apple’s NTP host time.apple.com, but I couldn’t find any official guidance about whether third-party apps may use time.apple.com directly (acceptable use, rate limits, whether it’s discouraged, etc.). Apple Developer Support couldn’t provide info and suggested asking on the forums. Questions: 1. Is it permitted for a third-party iOS app to query time.apple.com via NTP/SNTP (Yes/No or conditional)? 2. If permitted, are there any published or recommended constraints (rate limits, caching, prohibited patterns, commercial app considerations)? 3. If not permitted / not recommended, what is the recommended alternative approach (run our own time service, use public NTP pool, or any Apple-recommended mechanism)? 4. If there is any official document / policy covering this, could you point me to it? For context: I do not need sub-second accuracy and I do not intend high-frequency polling. If implemented at all, it would be very low frequency (e.g., first launch + once per 24h) with caching and graceful fallback on failure. My main goal is policy clarity rather than implementation details.
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Jan ’26
Does URLSession support ticket-based TLS session resumption
My company has a server that supports ticket-based TLS session resumption (per RFC 5077). We have done Wireshark captures that show that our iOS client app, which uses URLSession for REST and WebSocket connections to the server, is not sending the TLS "session_ticket" extension in the Client Hello package that necessary to enable ticket-based resumption with the server. Is it expected that URLSession does not support ticket-based TLS session resumption? If "yes", is there any way to tell URLSession to enable ticket-based session resumption? the lower-level API set_protocol_options_set_tls_tickets_enabled() hints that the overall TLS / HTTP stack on IOS does support ticket-based resumption, but I can't see how to use that low-level API with URLSession. I can provide (lots) more technical details if necessary, but hopefully this is enough context to determine whether ticket-based TLS resumption is supported with URLSession. Any tips / clarifications would be greatly appreciated.
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Aug ’25
Multipeer Connectivity support
Greetings.I have an app today that uses multipeer connectivity extensively. Currently, when the user switches away from the app, MPC disconnects the session(s) - this is by design apparently (per other feedback). I'd like to hear if anyone has experimented with iOS9 multitasking / multipeer and whether MPC sessions can stay alive?Thanks
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Jan ’26
Local Network permission on macOS 15 macOS 26: multicast behaves inconsistently and regularly drops
Problem description Since macOS Sequoia, our users have experienced issues with multicast traffic in our macOS app. Regularly, the app starts but cannot receive multicast, or multicast eventually stops mid-execution. The app sometimes asks again for Local Network permission, while it was already allowed so. Several versions of our app on a single machine are sometimes (but not always) shown as different instances in the System Settings > Privacy & Security > Local Network list. And when several instances are shown in that list, disabling one disables all of them, but it does not actually forbids the app from receiving multicast traffic. All of those issues are experienced by an increasing number of users after they update their system from macOS 14 to macOS 15 or 26, and many of them have reported networking issues during production-critical moments. We haven't been able to find the root cause of those issues, so we built a simple test app, called "FM Mac App Test", that can reproduce multicast issues. This app creates a GCDAsyncUdpSocket socket to receive multicast packets from a piece of hardware we also develop, and displays a simple UI showing if such packets are received. The app is entitled with "Custom Network Protocol", is built against x86_64 and arm64, and is archived (signed and notarized). We can share the source code if requested. Out of the many issues our main app exhibits, the test app showcases some: The app asks several times for Local Network permission, even after being allowed so previously. After allowing the app's Local Network and rebooting the machine, the System Settings > Privacy & Security > Local Network does not show the app, and the app asks again for Local Network access. The app shows a different Local Network Usage Description than in the project's plist. Several versions of the app appear as different instances in the Privacy list, and behave strangely. Toggling on or off one instance toggles the others. Only one version of the app seems affected by the setting, the other versions always seem to have access to Local Network even when the toggle is set to off. We even did see messages from different app versions in different user accounts. This seems to contradicts Apple's documentation that states user accounts have independent Privacy settings. Can you help us understand what we are missing (in terms of build settings, entitlements, proper archiving...) so our app conforms to what macOS expects for proper Local Network behavior? Related material Local Network Privacy breaks Application: this issue seemed related to ours, but the fix was to ensure different versions of the app have different UUIDs. We ensured that ourselves, to no improvement. Local Network FAQ Technote TN3179 Steps to Reproduce Test App is developed on Xcode 15.4 (15F31d) on macOS 14.5 (23F79), and runs on macOS 26.0.1 (25A362). We can share the source code if requested. On a clean install of macOS Tahoe (our test setup used macOS 26.0.1 on a Mac mini M2 8GB), we upload the app (version 5.1). We run the app, make sure the selected NIC is the proper one, and open the multicast socket. The app asks us to allow Local Network, we allow it. The alert shows a different Local Network Usage Description than the one we set in our project's plist. The app properly shows packets are received from the console on our LAN. We check the list in System Settings > Privacy & Security > Local Network, it includes our app properly allowed. We then reboot the machine. After reboot, the same list does not show the app anymore. We run the app, it asks again about Local Network access (still with incorrect Usage Description). We allow it again, but no console packet is received yet. Only after closing and reopening the socket are the console packets received. After a 2nd reboot, the System Settings > Privacy & Security > Local Network list shows correctly the app. The app seems to now run fine. We then upload an updated version of the same app (5.2), also built and notarized. The 2nd version is simulating when we send different versions of our main app to our users. The updated version has a different UUID than the 1st version. The updated version also asks for Local Network access, this time with proper Usage Description. A 3rd updated version of the app (5.3, also with unique UUID) behaves the same. The System Settings > Privacy & Security > Local Network list shows three instances of the app. We toggle off one of the app, all of them toggle off. The 1st version of the app (5.1) does not have local network access anymore, but both 2nd and 3rd versions do, while their toggle button seems off. We toggle on one of the app, all of them toggle on. All 3 versions have local network access.
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App Extension Network Extension - failed to start, signature check failed
Howdy, I've been developing a packet tunnel extension meant to run on iOS and MacOS. For development I'm using xcodegen + xcodebuild to assemble a bunch of swift and rust code together. I'm moving from direct TUN device management on Mac to shipping a Network Extension (appex). With that move I noticed that on some mac laptops NE fails to start completely, whilst on others everything works fine. I'm using CODE_SIGN_STYLE: Automatic, Apple IDs are within the same team, all devices are registered as dev devices. Signing dev certificates, managed by xcode. Some suspicious logs: (NetworkExtension) [com.apple.networkextension:] Signature check failed: code failed to satisfy specified code requirement(s) ... (NetworkExtension) [com.apple.networkextension:] Provider is not signed with a Developer ID certificate What could be the issue? Where those inconsistencies across devices might come from?
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Nov ’25
[iPadOS 26] EACCES (Permission Denied) on UDP Broadcast despite Multicast Networking Entitlement
My application (using a nested framework for networking) was working correctly on iPadOS 18, but failed to perform a UDP broadcast operation after upgrading the device to iPadOS 26. The low-level console logs consistently show a "Permission denied" error. Symptoms & Error Message: When attempting to send a UDP broadcast packet using NWConnection (or a similar low-level socket call within the framework), the connection fails immediately with the following error logged in the console: nw_socket_service_writes_block_invoke [C2:1] sendmsg(fd 6, 124 bytes) [13: Permission denied] (Error code 13 corresponds to EACCES). Verification Steps (What I have checked): Multicast Networking Entitlement is Approved and Applied: The necessary entitlement (com.apple.developer.networking.multicast) was granted by Apple. The Provisioning Profile used for signing the Host App Target has been regenerated and explicitly includes "Multicast Networking" capability (see attached screenshot). I confirmed that Entitlements cannot be added directly to the Framework Target, only the Host App Target, which is the expected behavior. Local Network Privacy is Configured: The Host App's Info.plist contains the NSLocalNetworkUsageDescription key with a clear usage string. Crucially, the Local Network Access alert does not reliably appear when the Broadcast function is first called (despite a full reinstall after OS upgrade). Even when Local Network Access is manually enabled in Settings, the Broadcast still fails with EACCES. Code Implementation: The Broadcast is attempted using NWConnection to the host 255.255.255.255 on a specific port. Request: Since all required entitlements and profiles are correct, and the failure is a low-level EACCES on a newly updated OS version, I suspect this may be a regression bug in the iPadOS 26 security sandbox when validating the Multicast Networking Entitlement against a low-level socket call (like sendmsg). Has anyone else encountered this specific Permission denied error on iPadOS 26 with a valid Multicast Entitlement, and is there a known workaround aside from switching to mDNS/Bonjour?
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Oct ’25
App Crashes on iOS 26 in Network.framework / boringssl – objc_release & memory corruption
Hello Apple Support Team, We are seeing a production crash on iOS 26 devices that appears to originate from Apple system frameworks rather than application code. 1. Crash Details OS Version: iOS 26.x App built with: Xcode 16 Devices: Multiple models (not device-specific) Exception Type: SIGSEGV SEGV_ACCERR Fault Address: 0x0000000000000100 Crashed Thread: 4 (network background queue) Crash trace summary: Last Exception : 0 libobjc.A.dylib _objc_release_x8 + 8 1 libboringssl.dylib _nw_protocol_boringssl_deallocate_options + 92 2 Network 0x000000019695207c 0x00000001968dc000 + 483452 3 libswiftCore.dylib __swift_release_dealloc + 56 4 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 5 Network 0x0000000196951f6c 0x00000001968dc000 + 483180 6 Network 0x0000000196952000 0x00000001968dc000 + 483328 7 libswiftCore.dylib __swift_release_dealloc + 56 8 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 9 libswiftCore.dylib void multiPayloadEnumFN<&handleRefCountsDestroy>(swift::TargetMetadata<swift::InProcess> const*, swift::LayoutStringReader1&, unsigned long&, unsigned char*) + 248 10 libswiftCore.dylib swift::swift_cvw_arrayDestroy(swift::OpaqueValue*, unsigned long, unsigned long, swift::TargetMetadata<swift::InProcess> const*) + 1172 11 libswiftCore.dylib _$sSp12deinitialize5countSvSi_tF + 40 12 CollectionsInternal ___swift_instantiateGenericMetadata + 1236 13 CollectionsInternal ___swift_instantiateGenericMetadata + 388 14 CollectionsInternal ___swift_instantiateGenericMetadata + 1044 15 libswiftCore.dylib __swift_release_dealloc + 56 16 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 17 Network 0x000000019695f9fc 0x00000001968dc000 + 539132 18 Network 0x000000019695f9bc 0x00000001968dc000 + 539068 19 libswiftCore.dylib __swift_release_dealloc + 56 20 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 21 libswiftCore.dylib swift_cvw_destroyImpl(swift::OpaqueValue*, swift::TargetMetadata<swift::InProcess> const*) + 212 22 Network 0x0000000196def5d8 0x00000001968dc000 + 5322200 23 Network 0x0000000196ded130 0x00000001968dc000 + 5312816 24 libswiftCore.dylib __swift_release_dealloc + 56 25 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 26 Network 0x000000019695fde0 0x00000001968dc000 + 540128 27 libobjc.A.dylib object_cxxDestructFromClass(objc_object*, objc_class*) + 116 28 libobjc.A.dylib objc_destructInstance_nonnull_realized(objc_object*) + 76 29 libobjc.A.dylib __objc_rootDealloc + 72 30 Network 0x000000019695f99c 0x00000001968dc000 + 539036 31 Network 0x000000019695fae4 0x00000001968dc000 + 539364 32 Network 0x0000000196b078b8 0x00000001968dc000 + 2275512 33 libobjc.A.dylib object_cxxDestructFromClass(objc_object*, objc_class*) + 116 34 libobjc.A.dylib objc_destructInstance_nonnull_realized(objc_object*) + 76 35 libobjc.A.dylib __objc_rootDealloc + 72 36 Network 0x0000000196b07658 0x00000001968dc000 + 2274904 37 Network 0x00000001968e51d4 nw_queue_context_async_if_needed + 92 38 Network 0x0000000197686ea0 0x00000001968dc000 + 14331552 39 libswiftCore.dylib swift::swift_cvw_arrayDestroy(swift::OpaqueValue*, unsigned long, unsigned long, swift::TargetMetadata<swift::InProcess> const*) + 436 40 libswiftCore.dylib _$sSp12deinitialize5countSvSi_tF + 40 41 CollectionsInternal ___swift_instantiateGenericMetadata + 1236 42 CollectionsInternal ___swift_instantiateGenericMetadata + 388 43 CollectionsInternal ___swift_instantiateGenericMetadata + 1044 44 libswiftCore.dylib __swift_release_dealloc + 56 45 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 46 Network 0x000000019694a010 0x00000001968dc000 + 450576 47 libobjc.A.dylib object_cxxDestructFromClass(objc_object*, objc_class*) + 116 48 libobjc.A.dylib objc_destructInstance_nonnull_realized(objc_object*) + 76 49 libobjc.A.dylib __objc_rootDealloc + 72 50 Network 0x0000000196a330e0 0x00000001968dc000 + 1405152 51 Network 0x00000001974378e0 0x00000001968dc000 + 11909344 52 Network 0x0000000196a17178 0x00000001968dc000 + 1290616 53 libdispatch.dylib __dispatch_call_block_and_release + 32 54 libdispatch.dylib __dispatch_client_callout + 16 55 libdispatch.dylib _dispatch_workloop_invoke.cold.4 + 32 56 libdispatch.dylib __dispatch_workloop_invoke + 1980 57 libdispatch.dylib __dispatch_root_queue_drain_deferred_wlh + 292 58 libdispatch.dylib __dispatch_workloop_worker_thread + 692 59 libsystem_pthread.dylib __pthread_wqthread + 292 ------ Exception Type: SIGSEGV SEGV_ACCERR Exception Codes: fault addr: 0x0000000000000100 Crashed Thread: 4 2. Behavior & Context The crash occurs during normal HTTPS networking using standard URLSession (no direct usage of Network.framework nor boringssl APIs). It appears to be triggered during QUIC connection establishment or TLS fallback. The stack trace contains no application code frames — all symbols are from system libraries. The crash strongly indicates double-free, over-release, or dangling pointer inside nw_protocol_boringssl_options deallocation. 3. Questions for Apple Is this a known issue in iOS 26 within Network.framework / boringssl related to nw_protocol_boringssl_deallocate_options? What is the root cause of the over‑release / invalid objc_release in this path? Is there a workaround we can implement from the app side (e.g., disabling QUIC, adjusting TLS settings, or queue configuration)? Do you have a target iOS version or patch where this issue will be fixed? We can provide full crash logs and additional metrics upon request. 4. Additional Information Developed using Swift 5, with a deployment target of iOS 12+. Thank you for your support.
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Mar ’26
Push notifications not delivered over Wi-Fi with includeAllNetworks = true regardless of excludeAPNS setting
We have a VPN app that uses NEPacketTunnelProvider with includeAllNetworks = true. We've encountered an issue where push notifications are not delivered over Wi-Fi while the tunnel is active in a pre-MFA quarantine state (tunnel is up but traffic is blocked on server side), regardless of whether excludeAPNS is set to true or false. Observed behavior Wi-Fi excludeAPNS = true - Notifications not delivered Wi-Fi excludeAPNS = false - Notifications not delivered Cellular excludeAPNS = true - Notifications delivered Cellular excludeAPNS = false - Notifications not delivered On cellular, the behavior matches our expectations: setting excludeAPNS = true allows APNS traffic to bypass the tunnel and notifications arrive; setting it to false routes APNS through the tunnel and notifications are blocked (as expected for a non-forwarding tunnel). On Wi-Fi, notifications fail to deliver in both cases. Our question Is this expected behavior when includeAllNetworks is enabled on Wi-Fi, or is this a known issue / bug with APNS delivery? Is there something else in the Wi-Fi networking path that includeAllNetworks affects beyond routing, which could prevent APNS from functioning even when the traffic is excluded from the tunnel? Sample Project Below is the minimal code that reproduces this issue. The project has two targets: a main app and a Network Extension. The tunnel provider captures all IPv4 and IPv6 traffic via default routes but does not forward packets — simulating a pre-MFA quarantine state. The main app configures the tunnel with includeAllNetworks = true and provides a UI toggle for excludeAPNS. PacketTunnelProvider.swift (Network Extension target): import NetworkExtension class PacketTunnelProvider: NEPacketTunnelProvider { override func startTunnel(options: [String : NSObject]?, completionHandler: @escaping (Error?) -> Void) { let settings = NEPacketTunnelNetworkSettings(tunnelRemoteAddress: "127.0.0.1") let ipv4 = NEIPv4Settings(addresses: ["198.51.100.1"], subnetMasks: ["255.255.255.0"]) ipv4.includedRoutes = [NEIPv4Route.default()] settings.ipv4Settings = ipv4 let ipv6 = NEIPv6Settings(addresses: ["fd00::1"], networkPrefixLengths: [64]) ipv6.includedRoutes = [NEIPv6Route.default()] settings.ipv6Settings = ipv6 let dns = NEDNSSettings(servers: ["198.51.100.1"]) settings.dnsSettings = dns settings.mtu = 1400 setTunnelNetworkSettings(settings) { error in if let error = error { completionHandler(error) return } self.readPackets() completionHandler(nil) } } private func readPackets() { packetFlow.readPackets { [weak self] packets, protocols in self?.readPackets() } } override func stopTunnel(with reason: NEProviderStopReason, completionHandler: @escaping () -> Void) { completionHandler() } override func handleAppMessage(_ messageData: Data, completionHandler: ((Data?) -> Void)?) { if let handler = completionHandler { handler(messageData) } } override func sleep(completionHandler: @escaping () -> Void) { completionHandler() } override func wake() { } } ContentView.swift (Main app target) — trimmed to essentials: import SwiftUI import NetworkExtension struct ContentView: View { @State private var excludeAPNs = false @State private var manager: NETunnelProviderManager? var body: some View { VStack { Toggle("Exclude APNs", isOn: $excludeAPNs) .onChange(of: excludeAPNs) { Task { await saveAndReload() } } Button("Connect") { Task { await toggleVPN() } } } .padding() .task { await loadManager() } } private func loadManager() async { let managers = try? await NETunnelProviderManager.loadAllFromPreferences() if let existing = managers?.first { manager = existing } else { let m = NETunnelProviderManager() let proto = NETunnelProviderProtocol() proto.providerBundleIdentifier = "<your-extension-bundle-id>" proto.serverAddress = "127.0.0.1" proto.includeAllNetworks = true proto.excludeAPNs = excludeAPNs m.protocolConfiguration = proto m.localizedDescription = "TestVPN" m.isEnabled = true try? await m.saveToPreferences() try? await m.loadFromPreferences() manager = m } if let proto = manager?.protocolConfiguration as? NETunnelProviderProtocol { excludeAPNs = proto.excludeAPNs } } private func saveAndReload() async { guard let manager else { return } if let proto = manager.protocolConfiguration as? NETunnelProviderProtocol { proto.includeAllNetworks = true proto.excludeAPNs = excludeAPNs } manager.isEnabled = true try? await manager.saveToPreferences() try? await manager.loadFromPreferences() } private func toggleVPN() async { guard let manager else { return } if manager.connection.status == .connected { manager.connection.stopVPNTunnel() } else { await saveAndReload() try? manager.connection.startVPNTunnel() } } } Steps to reproduce Build and run the sample project with above code on a physical iOS device. Connect to a Wi-Fi network. Set excludeAPNS = true using the toggle and tap Connect. Send a push notification to the device to a test app with remote notification capability (e.g., via a test push service or the push notification console). Observe that the notification is not delivered. Disconnect. Switch to cellular. Reconnect with the same settings. Send the same push notification — observe that it is delivered. Environment iOS 26.2 Xcode 26.2 Physical device (iPhone 15 Pro)
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311
Mar ’26
URLCache behavior for request with different header values
Greetings, I would like to understand this URLCache behavior for two different requests to the same end point but with a different header value. Here is a code with comment explaining the behavior. // Create a request to for a url. let url = URL(string: "https://&lt;my url&gt;?f=json")! var request = URLRequest(url: url) // Set custom header with a value. request.setValue("myvalue", forHTTPHeaderField: "CustomField") // Send request to get the response. let (data, response) = try await URLSession.shared.data(for: request) print("data: \(String(describing: String(data: data, encoding: .utf8)))") print("response: \(response)") // Create second request to the same url but with different value of custom header field. var request2 = URLRequest(url: url) request2.setValue("newvalue", forHTTPHeaderField: "CustomField") // Check the URL cache for second request and it returns the response // of the first request even though the second request has different header value. let cachedResponse = URLCache.shared.cachedResponse(for: request2) print("cachedResponse: \(cachedResponse?.response)") Is this a bug in URLCache that request headers are not matched while returning the response? Is this an expected behavior? If yes, why?
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1.7k
Aug ’25
macOS Tahoe: IPMonitor incorrectly re-ranks interfaces causing VPN DNS leaks
Description Enterprise users are experiencing VPN resource access failures after upgrading to macOS Tahoe. Investigation indicates that configd (specifically IPMonitor) is incorrectly re-ranking network interfaces after a connectivity failure with probe server. This results in DNS queries routing through the physical network adapter (en0) instead of the VPN virtual adapter, even while the tunnel is active. This behaviour is not seen in previous macOS versions. Steps to Reproduce: Connect to an enterprise VPN (e.g., Ivanti Secure Access). Trigger a transient network condition where the Apple probe server is unreachable. For example make the DNS server down for 30 sec. Observe the system routing DNS queries for internal resources to the physical adapter. Expected Results The: VPN virtual interface should maintain its primary rank for enterprise DNS queries regardless of the physical adapter's probe status. Actual Results: IPMonitor detects an UplinkIssue, deprioritizes the VPN interface, and elevates the physical adapter to a higher priority rank. Technical Root Cause & Logs: The system logs show IPMonitor identifying an issue and modifying the interface priority at 16:03:54: IPMonitor Detection: The process identifies an inability to reach the Apple probe server and marks en0 with an advisory: Log snippet 2026-01-06 16:03:53.956399+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] configd[594] SetInterfaceAdvisory(en0) = UplinkIssue (2) reason='unable to reach probe server' Interface Re-ranking: Immediately following, IPMonitor recalculates the rank, placing the physical service ID at a higher priority (lower numerical rank) than the VPN service ID (net.pulsesecure...): Log snippet 2026-01-06 16:03:53.967935+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] 0. en0 serviceID=50CD9266-B097-4664-BFE6-7BAFCC5E9DC0 addr=192.168.0.128 rank=0x200000d 2026-01-06 16:03:53.967947+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] 1. en0 serviceID=net.pulsesecure.pulse.nc.main addr=192.168.0.128 rank=0x2ffffff 3.Physical adapter Is selected as Primary Interface: 2026-01-06 16:03:53.968145+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] 50CD9266-B097-4664-BFE6-7BAFCC5E9DC0 is the new primary IPv4 configd[594]: 50CD9266-B097-4664-BFE6-7BAFCC5E9DC0 is the new primary DNS Packet Trace Evidence Wireshark confirms that DNS queries for enterprise-specific DNS servers are being originated from the physical IP (192.168.0.128) instead of the virtual adapter: Time: 16:03:54.084 Source: 192.168.0.128 (Physical Adapter) Destination: 172.29.155.115 (Internal VPN DNS Server) Result: Connectivity Failure (Queries sent outside the tunnel)
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3
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504
Activity
2w
When updating a VPN app with `includeAllNetworks`, the newer instance of the packet tunnel is not started via on-demand rules
When installing a new version the app while a tunnel is connected, seemingly the old packet tunnel process gets stopped but the new one does not come back up. Reportedly, a path monitor is reporting that the device has no connectivity. Is this the expected behavior? When installing an update from TestFlight or the App store, the packet tunnel instance from the old tunnel is stopped, but, due to the profile being on-demand and incldueAllNetworks, the path monitoring believes the device has no connectivity - so the new app is never downloaded. Is this the expected behavior? During development, the old packet tunnel gets stopped, the new app is installed, but the new packet tunnel is never started. To start it, the user has to toggle the VPN twice from the Settings app. The tunnel could be started from the VPN app too, if we chose to not take the path monitor into account, but then the user still needs to attempt to start the tunnel twice - it only works on the second try. As far as we can tell, the first time around, the packet tunnel never gets started, the app receives an update about NEVPNStatus being set to disconnecting yet NEVPNConnection does not throw. The behavior I was naively expecting was that the packet tunnel process would be stopped only when the new app is fully downloaded and when the update is installed, Are we doing something horribly wrong here?
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7
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3
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703
Activity
Jan ’26
AccessorySetupKit – WiFi picker – show accessories after factory reset?
Hi there, We’re developing a companion app for a smart home product that communicates over the user’s local network. To provision the device, it initially creates its own Wi-Fi network. The user joins this temporary network and enters their home Wi-Fi credentials via our app. The app then sends those credentials directly to the device, which stores them and connects to the local network for normal operation. We’re using AccessorySetupKit to discover nearby devices (via SSID prefix) and NEHotspotManager to join the accessory’s Wi-Fi network once the user selects it. This workflow works well in general. However, we’ve encountered a problem: if the user factory-resets the accessory, or needs to restart setup (for example, after entering the wrong Wi-Fi password), the device no longer appears in the accessory picker. In iOS 18, we were able to work around this by calling removeAccessory() after the device is selected. This forces the picker to always display the accessory again. But in iOS 26, a new confirmation dialog now appears when calling removeAccessory(), which confuses users during setup. We’re looking for a cleaner way to handle this scenario — ideally a way to make the accessory rediscoverable without prompting the user to confirm removal. Thanks for your time and guidance.
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0
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3
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285
Activity
Nov ’25
Disable URLSession auto retry policy
We are developing an iOS application that is interacting with HTTP APIs that requires us to put a unique UUID (a nonce) as an header on every request (obviously there's more than that, but that's irrilevant to the question here). If the same nonce is sent on two subsequent requests the server returns a 412 error. We should avoid generating this kind of errors as, if repeated, they may be flagged as a malicious activity by the HTTP APIs. We are using URLSession.shared.dataTaskPublisher(for: request) to call the HTTP APIs with request being generated with the unique nonce as an header. On our field tests we are seeing a few cases of the same HTTP request (same nonce) being repeated a few seconds on after the other. Our code has some retry logic only on 401 errors, but that involves a token refresh, and this is not what we are seeing from logs. We were able to replicate this behaviour on our own device using Network Link Conditioner with very bad performance, with XCode's Network inspector attached we can be certain that two HTTP requests with identical headers are actually made automatically, the first request has an "End Reason" of "Retry", the second is "Success" with Status 412. Our questions are: can we disable this behaviour? can we provide a new request for the retry (so that we can update headers)? Thanks, Francesco
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7
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3
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372
Activity
Aug ’25
Requesting URL Filtering capability
Hi Apple team, Could you please let us know the estimated timeline for approval of our OHTTP relay request? We’d appreciate any updates on the current status or next steps from your side. My request number is GZ8425KHD9. Thanks in advance.
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11
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0
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316
Activity
6d
iOS 26 Network Framework AWDL not working
Hello, I have an app that is using iOS 26 Network Framework APIs. It is using QUIC, TLS 1.3 and Bonjour. For TLS I am using a PKCS#12 identity. All works well and as expected if the devices (iPhone with no cellular, iPhone with cellular, and iPad no cellular) are all on the same wifi network. If I turn off my router (ie no more wifi network) and leave on the wifi toggle on the iOS devices - only the non cellular iPhone and iPad are able to discovery and connect to each other. My iPhone with cellular is not able to. By sharing my logs with Cursor AI it was determined that the connection between the two problematic peers (iPad with no cellular and iPhone with cellular) never even makes it to the TLS step because I never see the logs where I print out the certs I compare. I tried doing "builder.requiredInterfaceType(.wifi)" but doing that blocked the two non cellular devices from working. I also tried "builder.prohibitedInterfaceTypes([.cellular])" but that also did not work. Is AWDL on it's way out? Should I focus my energy on Wi-Fi Aware? Regards, Captadoh
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43
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0
Views
3k
Activity
1w
Xcode 16.4 and above build error with Network Extension and WireGuard library
I have added a Network Extension to my iOS project to use the WireGuard library. Everything was working fine up to Xcode 16, but after updating, I’m facing a build issue. The build fails with the following error: No such file or directory: '@rpath/WireGuardNetworkExtensioniOS.debug.dylib' I haven’t explicitly added any .dylib to my project. The Network Extension target builds and runs fine on Xcode 16.
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2
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3
Views
230
Activity
Sep ’25
NEAppProxyUDPFlow.writeDatagrams fails with "The datagram was too large" on macOS 15.x, macOS 26.x
I'm implementing a NEDNSProxyProvider on macOS 15.x and macOS 26.x. The flow works correctly up to the last step — returning the DNS response to the client via writeDatagrams. Environment: macOS 15.x, 26.x Xcode 26.x NEDNSProxyProvider with NEAppProxyUDPFlow What I'm doing: override func handleNewFlow(_ flow: NEAppProxyFlow) -> Bool { guard let udpFlow = flow as? NEAppProxyUDPFlow else { return false } udpFlow.readDatagrams { datagrams, endpoints, error in // 1. Read DNS request from client // 2. Forward to upstream DNS server via TCP // 3. Receive response from upstream // 4. Try to return response to client: udpFlow.writeDatagrams([responseData], sentBy: [endpoints.first!]) { error in // Always fails: "The datagram was too large" // responseData is 50-200 bytes — well within UDP limits } } return true } Investigation: I added logging to check the type of endpoints.first : // On macOS 15.0 and 26.3.1: // type(of: endpoints.first) → NWAddressEndpoint // Not NWHostEndpoint as expected On both macOS 15.4 and 26.3.1, readDatagrams returns [NWEndpoint] where each endpoint appears to be NWAddressEndpoint — a type that is not publicly documented. When I try to create NWHostEndpoint manually from hostname and port, and pass it to writeDatagrams, the error "The datagram was too large" still occurs in some cases. Questions: What is the correct endpoint type to pass to writeDatagrams on macOS 15.x, 26.x? Should we pass the exact same NWEndpoint objects returned by readDatagrams, or create new ones? NWEndpoint, NWHostEndpoint, and writeDatagrams are all deprecated in macOS 15. Is there a replacement API for NEAppProxyUDPFlow that works with nw_endpoint_t from the Network framework? Is the error "The datagram was too large" actually about the endpoint type rather than the data size? Any guidance would be appreciated. :-))
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7
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0
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222
Activity
Apr ’26
Network System Extension cannot use network interface of another VPN
Hi, Our project is a MacOS SwiftUI GUI application that bundles a (Sandboxed) System Network Extension, signed with a Developer ID certificate for distribution outside of the app store. The system network extension is used to write a packet tunnel provider (NEPacketTunnelProvider), as our project requires the creation of a TUN device. In order for our System VPN to function, it must reach out to a (self-hosted) server (i.e. to discover a list of peers). Being self-hosted, this server is typically not accessible via the public web, and may only be accessible from within a VPN (such as those also implemented using NEPacketTunnelProvider, e.g. Tailscale, Cloudflare WARP). What we've discovered is that the networking code of the System Network Extension process does not attempt to use the other VPN network interfaces (utunX) on the system. In practice, this means requests to IPs and hostnames that should be routed to those interfaces time out. Identical requests made outside of the Network System Extension process use those interfaces and succeed. The simplest example is where we create a URLSession.downloadTask for a resource on the server. A more complicated example is where we execute a Go .dylib that continues to communicate with that server. Both types of requests time out. Two noteworthy logs appear when packets fail to send, both from the kernel 'process': cfil_hash_entry_log:6088 <CFIL: Error: sosend_reinject() failed>: [30685 com.coder.Coder-Desktop.VPN] <UDP(17) out so b795d11aca7c26bf 57728068503033955 57728068503033955 age 0> lport 3001 fport 3001 laddr 100.108.7.40 faddr 100.112.177.88 hash 58B15863 cfil_service_inject_queue:4472 CFIL: sosend() failed 49 I also wrote some test code that probes using a UDP NWConnection and NWPath availableInterfaces. When run from the GUI App, multiple interfaces are returned, including the one that routes the address, utun5. When ran from within the sysex, only en0 is returned. I understand routing a VPN through another is unconventional, but we unfortunately do need this functionality one way or another. Is there any way to modify which interfaces are exposed to the sysex? Additionally, are these limitations of networking within a Network System Extension documented anywhere? Do you have any ideas why this specific limitation might exist?
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5
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2
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499
Activity
Jul ’25
Wi-Fi Aware Sample doesn't build in Xcode 26.0 beta
Hello, I'm trying to build the sample app from Building peer-to-peer apps that demonstrates Wi-Fi Aware. Upon downloading the example source code, opening it in Xcode 26.0 beta, and building the app, the compiler fails with: DeviceDiscoveryPairingView.swift:8:8 No such module 'DeviceDiscoveryUI' Is this a known issue? I know that DeviceDiscoveryUI was previously only a tvOS capability. Thanks
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2
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2
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151
Activity
Jun ’25
XPC doesn't work with network extension on app upgrade
Our app has a network extension (as I've mentioned lots 😄). We do an upgrade by downloading the new package, stopping & removing all of our components except for the network extension, and then installing the new package, which then loads a LaunchAgent causing the containing app to run. (The only difference between a new install and upgrade is the old extension is left running, but not having anything to tell it what to do, just logs and continues.) On some (but not all) upgrades... nothing ends up able to communicate via XPC with the Network Extension. My simplest cli program to talk to it gets Could not create proxy: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named blah was invalidated: failed at lookup with error 3 - No such process." UserInfo={NSDebugDescription=The connection to service named bla was invalidated: failed at lookup with error 3 - No such process.} Could not communicate with blah Restarting the extension by doing a kill -9 doesn't fix it; neither does restarting the control daemon. The only solution we've come across so far is rebooting. I filed FB11086599 about this, but has anyone thoughts about this?
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20
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2
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4.4k
Activity
1d
Is it allowed for a third-party iOS app to query time.apple.com (NTP/SNTP)? Any official usage guidance / rate limits?
I’m developing an iOS idle game (guild management). To detect manual device time changes that would break progression, I need a trusted “current real-world time” reference. I’m considering querying Apple’s NTP host time.apple.com, but I couldn’t find any official guidance about whether third-party apps may use time.apple.com directly (acceptable use, rate limits, whether it’s discouraged, etc.). Apple Developer Support couldn’t provide info and suggested asking on the forums. Questions: 1. Is it permitted for a third-party iOS app to query time.apple.com via NTP/SNTP (Yes/No or conditional)? 2. If permitted, are there any published or recommended constraints (rate limits, caching, prohibited patterns, commercial app considerations)? 3. If not permitted / not recommended, what is the recommended alternative approach (run our own time service, use public NTP pool, or any Apple-recommended mechanism)? 4. If there is any official document / policy covering this, could you point me to it? For context: I do not need sub-second accuracy and I do not intend high-frequency polling. If implemented at all, it would be very low frequency (e.g., first launch + once per 24h) with caching and graceful fallback on failure. My main goal is policy clarity rather than implementation details.
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2
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0
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146
Activity
Jan ’26
Does URLSession support ticket-based TLS session resumption
My company has a server that supports ticket-based TLS session resumption (per RFC 5077). We have done Wireshark captures that show that our iOS client app, which uses URLSession for REST and WebSocket connections to the server, is not sending the TLS "session_ticket" extension in the Client Hello package that necessary to enable ticket-based resumption with the server. Is it expected that URLSession does not support ticket-based TLS session resumption? If "yes", is there any way to tell URLSession to enable ticket-based session resumption? the lower-level API set_protocol_options_set_tls_tickets_enabled() hints that the overall TLS / HTTP stack on IOS does support ticket-based resumption, but I can't see how to use that low-level API with URLSession. I can provide (lots) more technical details if necessary, but hopefully this is enough context to determine whether ticket-based TLS resumption is supported with URLSession. Any tips / clarifications would be greatly appreciated.
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6
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2
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741
Activity
Aug ’25
Multipeer Connectivity support
Greetings.I have an app today that uses multipeer connectivity extensively. Currently, when the user switches away from the app, MPC disconnects the session(s) - this is by design apparently (per other feedback). I'd like to hear if anyone has experimented with iOS9 multitasking / multipeer and whether MPC sessions can stay alive?Thanks
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6
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1
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3.9k
Activity
Jan ’26
Local Network permission on macOS 15 macOS 26: multicast behaves inconsistently and regularly drops
Problem description Since macOS Sequoia, our users have experienced issues with multicast traffic in our macOS app. Regularly, the app starts but cannot receive multicast, or multicast eventually stops mid-execution. The app sometimes asks again for Local Network permission, while it was already allowed so. Several versions of our app on a single machine are sometimes (but not always) shown as different instances in the System Settings > Privacy & Security > Local Network list. And when several instances are shown in that list, disabling one disables all of them, but it does not actually forbids the app from receiving multicast traffic. All of those issues are experienced by an increasing number of users after they update their system from macOS 14 to macOS 15 or 26, and many of them have reported networking issues during production-critical moments. We haven't been able to find the root cause of those issues, so we built a simple test app, called "FM Mac App Test", that can reproduce multicast issues. This app creates a GCDAsyncUdpSocket socket to receive multicast packets from a piece of hardware we also develop, and displays a simple UI showing if such packets are received. The app is entitled with "Custom Network Protocol", is built against x86_64 and arm64, and is archived (signed and notarized). We can share the source code if requested. Out of the many issues our main app exhibits, the test app showcases some: The app asks several times for Local Network permission, even after being allowed so previously. After allowing the app's Local Network and rebooting the machine, the System Settings > Privacy & Security > Local Network does not show the app, and the app asks again for Local Network access. The app shows a different Local Network Usage Description than in the project's plist. Several versions of the app appear as different instances in the Privacy list, and behave strangely. Toggling on or off one instance toggles the others. Only one version of the app seems affected by the setting, the other versions always seem to have access to Local Network even when the toggle is set to off. We even did see messages from different app versions in different user accounts. This seems to contradicts Apple's documentation that states user accounts have independent Privacy settings. Can you help us understand what we are missing (in terms of build settings, entitlements, proper archiving...) so our app conforms to what macOS expects for proper Local Network behavior? Related material Local Network Privacy breaks Application: this issue seemed related to ours, but the fix was to ensure different versions of the app have different UUIDs. We ensured that ourselves, to no improvement. Local Network FAQ Technote TN3179 Steps to Reproduce Test App is developed on Xcode 15.4 (15F31d) on macOS 14.5 (23F79), and runs on macOS 26.0.1 (25A362). We can share the source code if requested. On a clean install of macOS Tahoe (our test setup used macOS 26.0.1 on a Mac mini M2 8GB), we upload the app (version 5.1). We run the app, make sure the selected NIC is the proper one, and open the multicast socket. The app asks us to allow Local Network, we allow it. The alert shows a different Local Network Usage Description than the one we set in our project's plist. The app properly shows packets are received from the console on our LAN. We check the list in System Settings > Privacy & Security > Local Network, it includes our app properly allowed. We then reboot the machine. After reboot, the same list does not show the app anymore. We run the app, it asks again about Local Network access (still with incorrect Usage Description). We allow it again, but no console packet is received yet. Only after closing and reopening the socket are the console packets received. After a 2nd reboot, the System Settings > Privacy & Security > Local Network list shows correctly the app. The app seems to now run fine. We then upload an updated version of the same app (5.2), also built and notarized. The 2nd version is simulating when we send different versions of our main app to our users. The updated version has a different UUID than the 1st version. The updated version also asks for Local Network access, this time with proper Usage Description. A 3rd updated version of the app (5.3, also with unique UUID) behaves the same. The System Settings > Privacy & Security > Local Network list shows three instances of the app. We toggle off one of the app, all of them toggle off. The 1st version of the app (5.1) does not have local network access anymore, but both 2nd and 3rd versions do, while their toggle button seems off. We toggle on one of the app, all of them toggle on. All 3 versions have local network access.
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20
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2
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982
Activity
3w
App Extension Network Extension - failed to start, signature check failed
Howdy, I've been developing a packet tunnel extension meant to run on iOS and MacOS. For development I'm using xcodegen + xcodebuild to assemble a bunch of swift and rust code together. I'm moving from direct TUN device management on Mac to shipping a Network Extension (appex). With that move I noticed that on some mac laptops NE fails to start completely, whilst on others everything works fine. I'm using CODE_SIGN_STYLE: Automatic, Apple IDs are within the same team, all devices are registered as dev devices. Signing dev certificates, managed by xcode. Some suspicious logs: (NetworkExtension) [com.apple.networkextension:] Signature check failed: code failed to satisfy specified code requirement(s) ... (NetworkExtension) [com.apple.networkextension:] Provider is not signed with a Developer ID certificate What could be the issue? Where those inconsistencies across devices might come from?
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8
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0
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336
Activity
Nov ’25
[iPadOS 26] EACCES (Permission Denied) on UDP Broadcast despite Multicast Networking Entitlement
My application (using a nested framework for networking) was working correctly on iPadOS 18, but failed to perform a UDP broadcast operation after upgrading the device to iPadOS 26. The low-level console logs consistently show a "Permission denied" error. Symptoms & Error Message: When attempting to send a UDP broadcast packet using NWConnection (or a similar low-level socket call within the framework), the connection fails immediately with the following error logged in the console: nw_socket_service_writes_block_invoke [C2:1] sendmsg(fd 6, 124 bytes) [13: Permission denied] (Error code 13 corresponds to EACCES). Verification Steps (What I have checked): Multicast Networking Entitlement is Approved and Applied: The necessary entitlement (com.apple.developer.networking.multicast) was granted by Apple. The Provisioning Profile used for signing the Host App Target has been regenerated and explicitly includes "Multicast Networking" capability (see attached screenshot). I confirmed that Entitlements cannot be added directly to the Framework Target, only the Host App Target, which is the expected behavior. Local Network Privacy is Configured: The Host App's Info.plist contains the NSLocalNetworkUsageDescription key with a clear usage string. Crucially, the Local Network Access alert does not reliably appear when the Broadcast function is first called (despite a full reinstall after OS upgrade). Even when Local Network Access is manually enabled in Settings, the Broadcast still fails with EACCES. Code Implementation: The Broadcast is attempted using NWConnection to the host 255.255.255.255 on a specific port. Request: Since all required entitlements and profiles are correct, and the failure is a low-level EACCES on a newly updated OS version, I suspect this may be a regression bug in the iPadOS 26 security sandbox when validating the Multicast Networking Entitlement against a low-level socket call (like sendmsg). Has anyone else encountered this specific Permission denied error on iPadOS 26 with a valid Multicast Entitlement, and is there a known workaround aside from switching to mDNS/Bonjour?
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1
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1
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272
Activity
Oct ’25
App Crashes on iOS 26 in Network.framework / boringssl – objc_release & memory corruption
Hello Apple Support Team, We are seeing a production crash on iOS 26 devices that appears to originate from Apple system frameworks rather than application code. 1. Crash Details OS Version: iOS 26.x App built with: Xcode 16 Devices: Multiple models (not device-specific) Exception Type: SIGSEGV SEGV_ACCERR Fault Address: 0x0000000000000100 Crashed Thread: 4 (network background queue) Crash trace summary: Last Exception : 0 libobjc.A.dylib _objc_release_x8 + 8 1 libboringssl.dylib _nw_protocol_boringssl_deallocate_options + 92 2 Network 0x000000019695207c 0x00000001968dc000 + 483452 3 libswiftCore.dylib __swift_release_dealloc + 56 4 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 5 Network 0x0000000196951f6c 0x00000001968dc000 + 483180 6 Network 0x0000000196952000 0x00000001968dc000 + 483328 7 libswiftCore.dylib __swift_release_dealloc + 56 8 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 9 libswiftCore.dylib void multiPayloadEnumFN<&handleRefCountsDestroy>(swift::TargetMetadata<swift::InProcess> const*, swift::LayoutStringReader1&, unsigned long&, unsigned char*) + 248 10 libswiftCore.dylib swift::swift_cvw_arrayDestroy(swift::OpaqueValue*, unsigned long, unsigned long, swift::TargetMetadata<swift::InProcess> const*) + 1172 11 libswiftCore.dylib _$sSp12deinitialize5countSvSi_tF + 40 12 CollectionsInternal ___swift_instantiateGenericMetadata + 1236 13 CollectionsInternal ___swift_instantiateGenericMetadata + 388 14 CollectionsInternal ___swift_instantiateGenericMetadata + 1044 15 libswiftCore.dylib __swift_release_dealloc + 56 16 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 17 Network 0x000000019695f9fc 0x00000001968dc000 + 539132 18 Network 0x000000019695f9bc 0x00000001968dc000 + 539068 19 libswiftCore.dylib __swift_release_dealloc + 56 20 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 21 libswiftCore.dylib swift_cvw_destroyImpl(swift::OpaqueValue*, swift::TargetMetadata<swift::InProcess> const*) + 212 22 Network 0x0000000196def5d8 0x00000001968dc000 + 5322200 23 Network 0x0000000196ded130 0x00000001968dc000 + 5312816 24 libswiftCore.dylib __swift_release_dealloc + 56 25 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 26 Network 0x000000019695fde0 0x00000001968dc000 + 540128 27 libobjc.A.dylib object_cxxDestructFromClass(objc_object*, objc_class*) + 116 28 libobjc.A.dylib objc_destructInstance_nonnull_realized(objc_object*) + 76 29 libobjc.A.dylib __objc_rootDealloc + 72 30 Network 0x000000019695f99c 0x00000001968dc000 + 539036 31 Network 0x000000019695fae4 0x00000001968dc000 + 539364 32 Network 0x0000000196b078b8 0x00000001968dc000 + 2275512 33 libobjc.A.dylib object_cxxDestructFromClass(objc_object*, objc_class*) + 116 34 libobjc.A.dylib objc_destructInstance_nonnull_realized(objc_object*) + 76 35 libobjc.A.dylib __objc_rootDealloc + 72 36 Network 0x0000000196b07658 0x00000001968dc000 + 2274904 37 Network 0x00000001968e51d4 nw_queue_context_async_if_needed + 92 38 Network 0x0000000197686ea0 0x00000001968dc000 + 14331552 39 libswiftCore.dylib swift::swift_cvw_arrayDestroy(swift::OpaqueValue*, unsigned long, unsigned long, swift::TargetMetadata<swift::InProcess> const*) + 436 40 libswiftCore.dylib _$sSp12deinitialize5countSvSi_tF + 40 41 CollectionsInternal ___swift_instantiateGenericMetadata + 1236 42 CollectionsInternal ___swift_instantiateGenericMetadata + 388 43 CollectionsInternal ___swift_instantiateGenericMetadata + 1044 44 libswiftCore.dylib __swift_release_dealloc + 56 45 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152 46 Network 0x000000019694a010 0x00000001968dc000 + 450576 47 libobjc.A.dylib object_cxxDestructFromClass(objc_object*, objc_class*) + 116 48 libobjc.A.dylib objc_destructInstance_nonnull_realized(objc_object*) + 76 49 libobjc.A.dylib __objc_rootDealloc + 72 50 Network 0x0000000196a330e0 0x00000001968dc000 + 1405152 51 Network 0x00000001974378e0 0x00000001968dc000 + 11909344 52 Network 0x0000000196a17178 0x00000001968dc000 + 1290616 53 libdispatch.dylib __dispatch_call_block_and_release + 32 54 libdispatch.dylib __dispatch_client_callout + 16 55 libdispatch.dylib _dispatch_workloop_invoke.cold.4 + 32 56 libdispatch.dylib __dispatch_workloop_invoke + 1980 57 libdispatch.dylib __dispatch_root_queue_drain_deferred_wlh + 292 58 libdispatch.dylib __dispatch_workloop_worker_thread + 692 59 libsystem_pthread.dylib __pthread_wqthread + 292 ------ Exception Type: SIGSEGV SEGV_ACCERR Exception Codes: fault addr: 0x0000000000000100 Crashed Thread: 4 2. Behavior & Context The crash occurs during normal HTTPS networking using standard URLSession (no direct usage of Network.framework nor boringssl APIs). It appears to be triggered during QUIC connection establishment or TLS fallback. The stack trace contains no application code frames — all symbols are from system libraries. The crash strongly indicates double-free, over-release, or dangling pointer inside nw_protocol_boringssl_options deallocation. 3. Questions for Apple Is this a known issue in iOS 26 within Network.framework / boringssl related to nw_protocol_boringssl_deallocate_options? What is the root cause of the over‑release / invalid objc_release in this path? Is there a workaround we can implement from the app side (e.g., disabling QUIC, adjusting TLS settings, or queue configuration)? Do you have a target iOS version or patch where this issue will be fixed? We can provide full crash logs and additional metrics upon request. 4. Additional Information Developed using Swift 5, with a deployment target of iOS 12+. Thank you for your support.
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1
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2
Views
163
Activity
Mar ’26
Push notifications not delivered over Wi-Fi with includeAllNetworks = true regardless of excludeAPNS setting
We have a VPN app that uses NEPacketTunnelProvider with includeAllNetworks = true. We've encountered an issue where push notifications are not delivered over Wi-Fi while the tunnel is active in a pre-MFA quarantine state (tunnel is up but traffic is blocked on server side), regardless of whether excludeAPNS is set to true or false. Observed behavior Wi-Fi excludeAPNS = true - Notifications not delivered Wi-Fi excludeAPNS = false - Notifications not delivered Cellular excludeAPNS = true - Notifications delivered Cellular excludeAPNS = false - Notifications not delivered On cellular, the behavior matches our expectations: setting excludeAPNS = true allows APNS traffic to bypass the tunnel and notifications arrive; setting it to false routes APNS through the tunnel and notifications are blocked (as expected for a non-forwarding tunnel). On Wi-Fi, notifications fail to deliver in both cases. Our question Is this expected behavior when includeAllNetworks is enabled on Wi-Fi, or is this a known issue / bug with APNS delivery? Is there something else in the Wi-Fi networking path that includeAllNetworks affects beyond routing, which could prevent APNS from functioning even when the traffic is excluded from the tunnel? Sample Project Below is the minimal code that reproduces this issue. The project has two targets: a main app and a Network Extension. The tunnel provider captures all IPv4 and IPv6 traffic via default routes but does not forward packets — simulating a pre-MFA quarantine state. The main app configures the tunnel with includeAllNetworks = true and provides a UI toggle for excludeAPNS. PacketTunnelProvider.swift (Network Extension target): import NetworkExtension class PacketTunnelProvider: NEPacketTunnelProvider { override func startTunnel(options: [String : NSObject]?, completionHandler: @escaping (Error?) -> Void) { let settings = NEPacketTunnelNetworkSettings(tunnelRemoteAddress: "127.0.0.1") let ipv4 = NEIPv4Settings(addresses: ["198.51.100.1"], subnetMasks: ["255.255.255.0"]) ipv4.includedRoutes = [NEIPv4Route.default()] settings.ipv4Settings = ipv4 let ipv6 = NEIPv6Settings(addresses: ["fd00::1"], networkPrefixLengths: [64]) ipv6.includedRoutes = [NEIPv6Route.default()] settings.ipv6Settings = ipv6 let dns = NEDNSSettings(servers: ["198.51.100.1"]) settings.dnsSettings = dns settings.mtu = 1400 setTunnelNetworkSettings(settings) { error in if let error = error { completionHandler(error) return } self.readPackets() completionHandler(nil) } } private func readPackets() { packetFlow.readPackets { [weak self] packets, protocols in self?.readPackets() } } override func stopTunnel(with reason: NEProviderStopReason, completionHandler: @escaping () -> Void) { completionHandler() } override func handleAppMessage(_ messageData: Data, completionHandler: ((Data?) -> Void)?) { if let handler = completionHandler { handler(messageData) } } override func sleep(completionHandler: @escaping () -> Void) { completionHandler() } override func wake() { } } ContentView.swift (Main app target) — trimmed to essentials: import SwiftUI import NetworkExtension struct ContentView: View { @State private var excludeAPNs = false @State private var manager: NETunnelProviderManager? var body: some View { VStack { Toggle("Exclude APNs", isOn: $excludeAPNs) .onChange(of: excludeAPNs) { Task { await saveAndReload() } } Button("Connect") { Task { await toggleVPN() } } } .padding() .task { await loadManager() } } private func loadManager() async { let managers = try? await NETunnelProviderManager.loadAllFromPreferences() if let existing = managers?.first { manager = existing } else { let m = NETunnelProviderManager() let proto = NETunnelProviderProtocol() proto.providerBundleIdentifier = "<your-extension-bundle-id>" proto.serverAddress = "127.0.0.1" proto.includeAllNetworks = true proto.excludeAPNs = excludeAPNs m.protocolConfiguration = proto m.localizedDescription = "TestVPN" m.isEnabled = true try? await m.saveToPreferences() try? await m.loadFromPreferences() manager = m } if let proto = manager?.protocolConfiguration as? NETunnelProviderProtocol { excludeAPNs = proto.excludeAPNs } } private func saveAndReload() async { guard let manager else { return } if let proto = manager.protocolConfiguration as? NETunnelProviderProtocol { proto.includeAllNetworks = true proto.excludeAPNs = excludeAPNs } manager.isEnabled = true try? await manager.saveToPreferences() try? await manager.loadFromPreferences() } private func toggleVPN() async { guard let manager else { return } if manager.connection.status == .connected { manager.connection.stopVPNTunnel() } else { await saveAndReload() try? manager.connection.startVPNTunnel() } } } Steps to reproduce Build and run the sample project with above code on a physical iOS device. Connect to a Wi-Fi network. Set excludeAPNS = true using the toggle and tap Connect. Send a push notification to the device to a test app with remote notification capability (e.g., via a test push service or the push notification console). Observe that the notification is not delivered. Disconnect. Switch to cellular. Reconnect with the same settings. Send the same push notification — observe that it is delivered. Environment iOS 26.2 Xcode 26.2 Physical device (iPhone 15 Pro)
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5
Boosts
1
Views
311
Activity
Mar ’26
URLCache behavior for request with different header values
Greetings, I would like to understand this URLCache behavior for two different requests to the same end point but with a different header value. Here is a code with comment explaining the behavior. // Create a request to for a url. let url = URL(string: "https://&lt;my url&gt;?f=json")! var request = URLRequest(url: url) // Set custom header with a value. request.setValue("myvalue", forHTTPHeaderField: "CustomField") // Send request to get the response. let (data, response) = try await URLSession.shared.data(for: request) print("data: \(String(describing: String(data: data, encoding: .utf8)))") print("response: \(response)") // Create second request to the same url but with different value of custom header field. var request2 = URLRequest(url: url) request2.setValue("newvalue", forHTTPHeaderField: "CustomField") // Check the URL cache for second request and it returns the response // of the first request even though the second request has different header value. let cachedResponse = URLCache.shared.cachedResponse(for: request2) print("cachedResponse: \(cachedResponse?.response)") Is this a bug in URLCache that request headers are not matched while returning the response? Is this an expected behavior? If yes, why?
Replies
8
Boosts
2
Views
1.7k
Activity
Aug ’25