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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.

Networking Documentation

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How to use DNSServiceReconfirmRecord?
TL;DR: How does one use DNSServiceReconfirmRecord() to invalidate mDNS state of a device that's gone offline? I'm using the DNSServiceDiscovery API (dns_sd.h) for a local P2P service. The problem I'm trying to solve is how to deal with a peer that abruptly loses connectivity, i.e. by turning off WiFi or simply by moving out of range or otherwise losing connectivity. In this situation there is of course no notification that the peer device has gone offline; it simply stops sending any packets. After my own timeout mechanism determines the peer is not responding, I mark it as offline in my own data structures. The problem is how to discover when/if it comes back online later. My DNSServiceBrowse callback won't be invoked because mDNS doesn't know the device went offline in the first place. I am trying to use DNSServiceReconfirmRecord, which appears to be for exactly this use case -- "Instruct the daemon to verify the validity of a resource record that appears to be out of date (e.g. because TCP connection to a service's target failed.)" However my attempts always return a BadReference error (-65541). The function requires me to pass a DNS record, and the only one I know is the TXT record; perhaps it needs a different one? Which, and how would I get it? Thanks!
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197
Feb ’26
Stumped by URLSession behaviour I don't understand...
I have an app that has been using the following code to down load audio files: if let url = URL(string: episode.fetchPath()) { var request = URLRequest(url: url) request.httpMethod = "get" let task = session.downloadTask(with: request) And then the following completionHandler code: func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) { try FileManager.default.moveItem(at: location, to: localUrl) In the spirit of modernization, I'm trying to update this code to use async await: var request = URLRequest(url: url) request.httpMethod = "get" let (data, response) = try await URLSession.shared.data(for: request) try data.write(to: localUrl, options: [.atomicWrite, .completeFileProtection]) Both these code paths use the same url value. Both return the same Data blobs (they return the same hash value) Unfortunately the second code path (using await) introduces a problem. When the audio is playing and the iPhone goes to sleep, after 15 seconds, the audio stops. This problem does not occur when running the first code (using the didFinish completion handler) Same data, stored in the same URL, but using different URLSession calls. I would like to use async/await and not have to experience the audio ending after just 15 seconds of the device screen being asleep. any guidance greatly appreciated.
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638
Jan ’26
Network Framework: Choosing Interface Types for Browsing/ Advertising
I am using Network framework for connecting two iPad devices that are connected through LAN and has Wifi enabled. I have enabled peerToPeerIncluded. I would like to understand how the framework chooses the interface types for browsing and discovering devices. When I start a browser with browser.run or listener.run, does the browser and advertiser browse and listen on all available interface types? My concern is that if it does in only one interface, Is there a chance that the browser is browsing in one interface(Lets say WiredEthernet) and the listener is listening on another interface(Lets say AWDL) and they dont discover?
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178
Mar ’26
Network Framework peer to peer limitations
Hi all, We've been exploring the capabilities of the Network.framework for peer-to-peer communication and have run into some behavior that we haven't been able to fully explain with the existing documentation. In our tests, we’re working with 12 iOS devices, all disconnected from Wi-Fi to force communication over Apple Wireless Direct Link (AWDL). While using the Network.framework to create peer-to-peer connections, we observed that the number of connected peers never exceeded 8, despite all 12 devices being active and configured identically. Some questions we’re hoping to get clarification or discussion on: Is there a known upper limit to the number of peer-to-peer connections supported via AWDL? Are there conditions under which the framework or system limits or throttles visible peers? Does AWDL behavior vary by hardware model, iOS version, or backgrounding state of the app? Is there any official documentation or guidance around peer discovery or connection limits when using NWBrowser and NWConnection in a peer-to-peer context? We’d appreciate any insights from the Apple engineering team or other developers who have worked with larger peer groups using Network.framework in peer-to-peer mode.
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250
May ’25
MultiPeer Connectivity: Device discovery succeeds but handshake fails when off-network
Hi, I am building an app that depends on multiple iOS devices connecting to a designated "coordinator" iOS device. I am using MPC, and it works great when the devices are connected to the same WiFi AP, with virtually 100% connection success. My definition of success is a near instant detection of available devices, >95% connection success rate, and a stable ongoing connection with no unexpected disconnects. The issue arises when the devices are not connected to the same WiFi network (or connected to no network with WiFi and bluetooth still on). Devices detect each other immediately, but when initiating a connection, both devices initiate a handshake, but the connection is not successful. In the few times where the connection succeeds, the connection quality is high, stable, and doesn't drop. Is this a known limitation of the framework? Could I be doing something wrong in my implementation?
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237
Dec ’25
URLSessionDownloadTaskDelegate functions not called when using URLSession.download(for:), but works when using URLSession.downloadTask(with:)
I'm struggling to understand why the async-await version of URLSession download task APIs do not call the delegate functions, whereas the old non-async version that returns a reference to the download task works just fine. Here is my sample code: class DownloadDelegate: NSObject, URLSessionDownloadDelegate { func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) { // This only prints the percentage of the download progress. let calculatedProgress = Float(totalBytesWritten) / Float(totalBytesExpectedToWrite) let formatter = NumberFormatter() formatter.numberStyle = .percent print(formatter.string(from: NSNumber(value: calculatedProgress))!) } } // Here's the VC. final class DownloadsViewController: UIViewController { private let url = URL(string: "https://pixabay.com/get/g0b9fa2936ff6a5078ea607398665e8151fc0c10df7db5c093e543314b883755ecd43eda2b7b5178a7e613a35541be6486885fb4a55d0777ba949aedccc807d8c_1280.jpg")! private let delegate = DownloadDelegate() private lazy var session = URLSession(configuration: .default, delegate: delegate, delegateQueue: nil) // for the async-await version private var task: Task<Void, Never>? // for the old version private var downloadTask: URLSessionDownloadTask? override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) task?.cancel() task = nil task = Task { let (_, _) = try! await session.download(for: URLRequest(url: url)) self.task = nil } // If I uncomment this, the progress listener delegate function above is called. // downloadTask?.cancel() // downloadTask = nil // downloadTask = session.downloadTask(with: URLRequest(url: url)) // downloadTask?.resume() } } What am I missing here?
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2.1k
May ’25
Network issues in macOS 26.4 (25E5218f)
Since updating to macOS 26.4 developerbeta 2 I've been getting full loss of dns resolution. I am not running a VPN or any network extensions that I am aware of. I'm not sure how to report this in the feedback utility as I cannot find an appropriate category for it. Happy to file it if someone can give an appropriate suggestion - the closest I could see was Wi-Fi but that wanted Wi-Fi logs for the issue, which I do not believe to be needed as this is not a Wi-Fi connectivity issue. Running dig example.com +short nslookup example.com ping example.com Gives the following output 104.18.27.120 104.18.26.120 Server: 10.0.1.1 Address: 10.0.1.1#53 \ Non-authoritative answer: Name: example.com Address: 104.18.26.120 Name: example.com Address: 104.18.27.120 \ ping: cannot resolve example.com: Unknown host This shows it's not an issue with my local network and that core networking is working, but something in the mDNSResponder/dns stack of macOS is failing. This causes all apps/browsers that do not implement their own DNS lookups to fail (Chrome still works). Sometimes the issue clears after running the following commands (for a period), sometimes it does not. A restart always resolves the issue temporarily. sudo killall -9 mDNSResponder sudo killall -9 mDNSResponderHelper sudo dscacheutil -flushcache sudo ifconfig en0 down sudo ifconfig en0 up
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Mar ’26
DTLS Handshake Fails When App Is in Background – Is This an iOS Limitation?
Hello, We are facing an issue with performing a DTLS handshake when our iOS application is in the background. Our app (Vocera Collaboration Suite – VCS) uses secure DTLS-encrypted communication for incoming VoIP calls. Problem Summary: When the app is in the background and a VoIP PushKit notification arrives, we attempt to establish a DTLS handshake over our existing socket. However, the handshake consistently fails unless the app is already in the foreground. Once the app is foregrounded, the same DTLS handshake logic succeeds immediately. Key Questions: Is performing a DTLS handshake while the app is in the background technically supported by iOS? Or is this an OS-level limitation by design? If not supported, what is the Apple-recommended alternative to establish secure DTLS communication for VoIP flows without bringing the app to the foreground? Any guidance or clarification from Apple engineers or anyone who has solved a similar problem would be greatly appreciated. Thank you.
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367
Feb ’26
Local network access is blocked when two almost identical apps are installed
We are developing an enterprise app that connects to a local server. It uses simple URLSessions. There is a view in the app where you enter the server url (IP address) and a connection check is made. iOS asks for permission to access the local network. Everything works. If the server is reachable, the connection info is saved. Recently we encountered a very strange issue: We also have a beta version of this app. If we first install the normal version on a device, enter the server IP, save, and then install the beta version and do the same there: It does not get a connection (it waits for the timeout). The strange part is: If I try to configure the connection in the normal version again, it also does not work, it just waits for the timeout. The really strange part: When I delete the beta version, while the normal version is waiting for its connection, the connection succeeds immediately. Both versions have a different display name, bundle id. I also tried using a device that is not in our MDM: same problem. Even the iOS version seems to have no impact: I tried on iOS 15, 18 and 26. Is there an explanation and hopefully also a solution to this problem?
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Dec ’25
NetworkConnection throws EINVAL when receiving ping/pong control frames
Summary NetworkConnection<WebSocket> in iOS 26 Network framework throws POSIXErrorCode(rawValue: 22): Invalid argument when receiving WebSocket ping (opcode 9) or pong (opcode 10) control frames. This prevents proper WebSocket keep-alive functionality. Environment iOS 26.0 (Simulator) macOS 26.1 Xcode 26.0 Note: This issue was initially discovered on iOS 26 Simulator. The same behavior was confirmed on macOS 26, suggesting a shared bug in the Network framework. The attached sample code is for macOS for easier reproduction. Description When using the new NetworkConnection<WebSocket> API introduced in iOS 26 or macOS 26, the receive() method throws EINVAL error whenever a ping or pong control frame is received from the server. This is a critical issue because: WebSocket servers commonly send ping frames to keep connections alive Clients send ping frames to verify connection health The receive callback never receives the ping/pong frame - the error occurs before the frame reaches user code Steps to Reproduce Create a WebSocket connection to any server that supports ping/pong (e.g., wss://echo.websocket.org): import Foundation import Network // MARK: - WebSocket Ping/Pong EINVAL Bug Reproduction // This sample demonstrates that NetworkConnection<WebSocket> throws EINVAL // when receiving ping or pong control frames. @main struct WebSocketPingPongBug { static func main() async { print("=== WebSocket Ping/Pong EINVAL Bug Reproduction ===\n") do { try await testPingPong() } catch { print("Test failed with error: \(error)") } } static func testPingPong() async throws { let host = "echo.websocket.org" let port: UInt16 = 443 print("Connecting to wss://\(host)...") let endpoint = NWEndpoint.hostPort( host: NWEndpoint.Host(host), port: NWEndpoint.Port(rawValue: port)! ) try await withNetworkConnection(to: endpoint, using: { WebSocket { TLS { TCP() } } }) { connection in print("Connected!\n") // Start receive loop in background let receiveTask = Task { var messageCount = 0 while !Task.isCancelled { do { let (data, metadata) = try await connection.receive() messageCount += 1 print("[\(messageCount)] Received frame - opcode: \(metadata.opcode)") if let text = String(data: data, encoding: .utf8) { print("[\(messageCount)] Content: \(text)") } else { print("[\(messageCount)] Binary data: \(data.count) bytes") } } catch let error as NWError { if case .posix(let code) = error, code == .EINVAL { print("❌ EINVAL error occurred! (POSIXErrorCode 22: Invalid argument)") print(" This is the bug - ping/pong frame caused EINVAL") // Continue to demonstrate workaround continue } print("Receive error: \(error)") break } catch { print("Receive error: \(error)") break } } } // Wait for initial message from server try await Task.sleep(for: .seconds(2)) // Test 1: Send text message (should work) print("\n--- Test 1: Sending text message ---") try await connection.send("Hello, WebSocket!") print("✅ Text message sent") try await Task.sleep(for: .seconds(1)) // Test 2: Send ping (pong response will cause EINVAL) print("\n--- Test 2: Sending ping frame ---") print("Expecting EINVAL when pong is received...") let pingMetadata = NWProtocolWebSocket.Metadata(opcode: .ping) try await connection.ping(Data()) { pingMetadata } print("✅ Ping sent, waiting for pong...") // Wait for pong response try await Task.sleep(for: .seconds(2)) // Cleanup receiveTask.cancel() print("\n=== Test Complete ===") print("If you saw 'EINVAL error occurred!' above, the bug is reproduced.") } } } The receive() call fails with error when pong arrives: ❌ EINVAL error occurred! (POSIXErrorCode 22: Invalid argument) Test Results Scenario Result Send/receive text (opcode 1) ✅ OK Client sends ping, receives pong ❌ EINVAL on pong receive Expected Behavior The receive() method should successfully return ping and pong frames, or at minimum, handle them internally without throwing an error. The autoReplyPing option should allow automatic pong responses without disrupting the receive loop. Actual Behavior When a ping or pong control frame is received: The receive() method throws NWError.posix(.EINVAL) The frame never reaches user code (no opcode check is possible) The connection remains valid, but the receive loop is interrupted Workaround Catch the EINVAL error and restart the receive loop: while !Task.isCancelled { do { let received = try await connection.receive() // Process message } catch let error as NWError { if case .posix(let code) = error, code == .EINVAL { // Control frame caused EINVAL, continue receiving continue } throw error } } This workaround allows continued operation but: Cannot distinguish between ping-related EINVAL and other EINVAL errors Cannot access the ping/pong frame content Cannot implement custom ping/pong handling Impact WebSocket connections to servers that send periodic pings will experience repeated EINVAL errors Applications must implement workarounds that may mask other legitimate errors Additional Information Packet capture confirms ping/pong frames are correctly transmitted at the network level The error occurs in the Network framework's internal processing, before reaching user code
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285
Dec ’25
Wi-Fi Raw Socket Disconnection Issue on iPhone 17 Series
On my iPhone 16 Pro and iPhone 16 Pro Max devices, running iOS 26.0, 26.0.1, and 26.1, Wi-Fi raw socket communication works flawlessly. Even after keeping the connection active for over 40 minutes, there are no disconnections during data transmission. However, on the iPhone 17 and iPhone 17 Pro, the raw socket connection drops within 20 seconds. Once it disconnects, the socket cannot reconnect unless the Wi-Fi module itself is reset. I believe this issue is caused by a bug in the iPhone 17 series’ communication module. I have looked into many cases, and it appears to be related to a bug in the N1 chipset. Are there any possible solutions or workarounds for this issue?
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390
Mar ’26
Accessory Setup Kit (BLE) not showing multiple options nor the advertising name
I'm developing an application using the accessory setup kit (BLE) on iOS 18+. An important aspect of the connection process is being able to find and choose the correct device. I noticed on iOS 18.2 that I was able to both scroll through the discovered accessories as well as view the advertised name. However, after upgrading to 18.7.2, only a single device is viewable and the advertised name is no longer available. Is there a trigger for this feature that I need to enable or was this "multiple discovery" feature removed? If so, why?
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232
Oct ’25
URL filter app with multiple configurations
Hello, We've been working on an app that uses the new NEUrlFilter API and we've got a question. Currently, the system is designed with the assumption that a single app == usecase == single remote database. But what if we would like to give the user the ability to use different blocklists? For example, the user may want to: Block scam domains Block tracking domains Block adult domains Or any composition of these 3 What should we do to give the user this option? It seems that we could differentiate different databases by using different PIR service hostnames, but that would also mean that we'll have to send several requests for the same usecase but with different PIR service hostnames (and they'll all share the same app bundle ID). Will these requests be accepted then? If not, is there an alternative? PS: By sending a request I mean submitting this form
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159
Oct ’25
DeviceDiscoveryUI and Bonjour for iOS
I have some confusion around the usage of DeviceDiscoveryUI. The documentation suggests that it is available only on TVOS. But with the recent announcement of WifiAware, it has been used in iOS devices as well. Within DeviceDiscoveryUI, the DevicePicker or the DevicePairingView documentation seems to be available with iOS. Is this just a documentation mistake? Followup - Can I use DeviceDiscoveryUI's DevicePicker/ DevicePairingView to discover devices through Bonjour and then establish a connection through Network framework?
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193
Oct ’25
Network access blocked by system
I’m building an app on macOS 26.4 with Xcode 26.4. When I build and run my app it started prompting me for network access, which it didn’t do before with Xcode 26. It did that repeatedly, and I had been approving the prompts and the app had been working. Now the app’s network features are not working, and I assume its because its being blocked by macOS, even though I accepted the network requests each time. In System Settings - Privacy and Security - Local Network, the app has many repeated entries, like 20, and all of them are turned on.
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Crash in URLConnectionLoader::loadWithWhatToDo
There are multiple report of crashes on URLConnectionLoader::loadWithWhatToDo. The crashed thread in the stack traces pointing to calls inside CFNetwork which seems to be internal library in iOS. The crash has happened quite a while already (but we cannot detect when the crash started to occur) and impacted multiple iOS versions recorded from iOS 15.4 to 18.4.1 that was recorded in Xcode crash report organizer so far. Unfortunately, we have no idea on how to reproduce it yet but the crash keeps on increasing and affect more on iOS 18 users (which makes sense because many people updated their iOS to the newer version) and we haven’t found any clue on what actually happened and how to fix it on the crash reports. What we understand is it seems to come from a network request that happened to trigger the crash but we need more information on what (condition) actually cause it and how to solve it. Hereby, I attach sample crash report for both iOS 15 and 18. I also have submitted a report (that include more crash reports) with number: FB17775979. Will appreciate any insight regarding this issue and any resolution that we can do to avoid it. iOS 15.crash iOS 18.crash
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726
Jan ’26
`NEProxySettings.matchDomains` / `exceptionList` not working as expected in `NEPacketTunnelProvider` (domain-scoped proxy not applied, and exceptions not bypassed)
I’m working on an iOS Network Extension where a NEPacketTunnelProviderconfigures a local HTTP/HTTPS proxy usingNEPacketTunnelNetworkSettings.proxySettings. Per NEProxySettings.exceptionList docs: If the destination host name of an HTTP connection matches one of these patterns then the proxy settings will not be used for the connection. However, I’m seeing two distinct issues: Issue A (exception bypass not working): HTTPS traffic to a host that matches exceptionList still reaches the proxy. Issue B (domain-scoped proxy not applied): When matchDomains is set to match a specific domain (example: ["googlevideo.com"]), I still observe its traffic in some apps is not proxied. If I remove the domain from matchDomains, the same traffic is proxied. Environment OS: iOS (reproduced with 26.4 and other versions) Devices: Reproduced with several iPhones (likely iPads as well) Xcode: 26.3 Extension: NEPacketTunnelProvider Minimal Repro (code) This is the minimal configuration. Toggle between CONFIG A / CONFIG B to reproduce each issue. import NetworkExtension final class PacketTunnelProvider: NEPacketTunnelProvider { override func startTunnel( options: [String : NSObject]? = nil, completionHandler: @escaping (Error?) -> Void ) { let proxyPort = 12345 // proxy listening port let settings = NEPacketTunnelNetworkSettings(tunnelRemoteAddress: "8.8.8.8") let proxySettings = NEProxySettings() proxySettings.httpEnabled = true proxySettings.httpsEnabled = true proxySettings.httpServer = NEProxyServer(address: "1.2.3.4", port: proxyPort) // proxy listening address proxySettings.httpsServer = NEProxyServer(address: "1.2.3.4", port: proxyPort) // proxy listening address // CONFIG A: proxy all domains, but exclude some domains // proxySettings.matchDomains can be set to match all domains // proxySettings.exceptionList = ["*.cdninstagram.com", "cdninstagram.com"] // CONFIG B: proxy only a specific domain // proxySettings.matchDomains = ["googlevideo.com"] settings.proxySettings = proxySettings setTunnelNetworkSettings(settings) { error in completionHandler(error) } } } Repro steps Issue A (exceptionList bypass not working) Enable the VPN configuration and start the tunnel with CONFIG A (exceptionList = ["*.cdninstagram.com", "cdninstagram.com"]). Open the Instagram app to trigger HTTPS connections to *.cdninstagram.com Inspect proxy logs: cdninstagram.com traffic is still received by the proxy. Safari comparison: If I access URLs that trigger the same *.cdninstagram.com hosts from Safari, it can behave as expected. When the traffic is triggered from the Instagram app, the excluded host still reaches the proxy as CONNECT, which is unexpected. Issue B (matchDomains not applied for YouTube traffic) Start the tunnel with CONFIG B (matchDomains = ["googlevideo.com"]). Open the YouTube app and start playing a video (traffic typically targets *.googlevideo.com). Inspect proxy logs: googlevideo.com traffic is not received by the proxy. Remove the host from matchDomains and observe that googlevideo.com traffic is received by the proxy. Safari comparison: If I access a googlevideo.com host from Safari while matchDomains = ["googlevideo.com"], it behaves as expected (proxied). In contrast, the YouTube app’s googlevideo.com traffic is not proxied unless I match all domains. Expected Issue A Connections to *.cdninstagram.com in the Instagram app should not use the proxy and should not reach the local proxy server. Issue B With matchDomains = ["googlevideo.com"], traffic to *.googlevideo.com (YouTube video traffic) should be proxied and therefore reach the local proxy. Actual Issue A The local proxy still receives the request as: CONNECT scontent-mad1-1.cdninstagram.com:443 HTTP/1.1 So the bypass does not happen. Issue B With matchDomains = ["googlevideo.com"], I still observe googlevideo.com traffic in the YouTube app that is not delivered to the proxy. When all traffic is proxied, the same traffic is delivered to the proxy.
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Kernel panics on M5 devices with network extension
Hello, We have a security solution which intercepts network traffic for inspection using a combination of Transparent Proxy Provider and Content filter. Lately we are seeing reports from the market that on M5 Macbooks and A18 Neos the system will kernel panic using our solution, even though it never happens on M1-M4 and no significant code changes were made in the mean time. All crashes seem to be related to an internal double free in the kernel: panic(cpu 0 caller 0xfffffe003bb68224): skmem_slab_free_locked: attempt to free invalid or already-freed obj 0xf2fffe29e15f2400 on skm 0xf6fffe2518aaa200 @skmem_slab.c:646 Debugger message: panic Memory ID: 0xff OS release type: User OS version: 25D2128 Kernel version: Darwin Kernel Version 25.3.0: Wed Jan 28 20:54:38 PST 2026; root:xnu-12377.91.3~2/RELEASE_ARM64_T6050 Additionally, from further log inspection, before panics we find some weird kernel messages which seem to be related to some DMA operations gone wrong in the network driver on some machines: 2026-03-30 14:11:21.779124+0300 0x30f2 Default 0x0 873 0 Arc: (Network) [com.apple.network:connection] [C9.1.1.1 IPv4#e5b4bb04:443 in_progress socket-flow (satisfied (Path is satisfied), interface: en0[802.11], ipv4, ipv6, dns, uses wifi, flow divert agg: 1, LQM: good)] event: flow:start_connect @0.075s 2026-03-30 14:11:21.780015+0300 0x1894 Default 0x0 0 0 kernel: (402262746): No more valid control units, disabling flow divert 2026-03-30 14:11:21.780017+0300 0x1894 Default 0x0 0 0 kernel: (402262746): Skipped all flow divert services, disabling flow divert 2026-03-30 14:11:21.780102+0300 0x1894 Default 0x0 0 0 kernel: SK[2]: flow_entry_alloc fe "0 proc kernel_task(0)Arc nx_port 1 flow_uuid D46E230E-B826-4E0A-8C59-4C4C8BF6AA60 flags 0x14120<CONNECTED,QOS_MARKING,EXT_PORT,EXT_FLOWID> ipver=4,src=<IPv4-redacted>.49703,dst=<IPv4-redacted>.443,proto=0x06 mask=0x0000003f,hash=0x04e0a750 tp_proto=0x06" 2026-03-30 14:11:21.780194+0300 0x1894 Default 0x0 0 0 kernel: tcp connect outgoing: [<IPv4-redacted>:49703<-><IPv4-redacted>:443] interface: en0 (skipped: 0) so_gencnt: 14634 t_state: SYN_SENT process: Arc:873 SYN in/out: 0/1 bytes in/out: 0/0 pkts in/out: 0/0 rtt: 0.0 ms rttvar: 250.0 ms base_rtt: 0 ms error: 0 so_error: 0 svc/tc: 0 flow: 0x9878386f 2026-03-30 14:11:21.934431+0300 0xed Default 0x0 0 0 kernel: Hit error condition (not panicking as we're in error handler): t8110dart <private> (dart-apcie0): invalid SID 2 TTBR access: level 1 table_index 0 page_offset 0x2 2026-03-30 14:11:21.934432+0300 0xed Default 0x0 0 0 kernel: [ 73.511690]: arm_cpu_init(): cpu 6 online 2026-03-30 14:11:21.934441+0300 0xed Default 0x0 0 0 kernel: [ 73.511696]: arm_cpu_init(): cpu 9 online 2026-03-30 14:11:21.934441+0300 0xed Default 0x0 0 0 kernel: [ 73.569033]: arm_cpu_init(): cpu 6 online 2026-03-30 14:11:21.934441+0300 0xed Default 0x0 0 0 kernel: [ 73.569038]: arm_cpu_init(): cpu 9 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.577453]: arm_cpu_init(): cpu 7 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.586328]: arm_cpu_init(): cpu 5 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.586332]: arm_cpu_init(): cpu 8 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.621392]: (dart-apcie0) AppleT8110DART::_fatalException: dart-apcie0 (<ptr>): DART DART SID exception ERROR_SID_SUMMARY 0x00003000 ERROR_ADDRESS 0x0000000000009800 2026-03-30 14:11:21.934443+0300 0xed Default 0x0 0 0 kernel: [ 73.621397]: Hit error condition (not panicking as we're in error handler): 2026-03-30 14:11:21.934443+0300 0xed Default 0x0 0 0 kernel: t8110dart <ptr> (dart-apcie0): invalid SID 2 TTBR access: level 1 table_index 0 page_offset 0x2Expect a `deadbeef` in the error messages below 2026-03-30 14:11:21.934452+0300 0xed Default 0x0 0 0 kernel: Expect a `deadbeef` in the error messages below 2026-03-30 14:11:21.934456+0300 0xed Default 0x0 0 0 kernel: (AppleEmbeddedPCIE) apcie[0:centauri-control]::_dartErrorHandler() InvalidPTE caused by read from address 0x9800 by SID 2 (RID 2:0:1/useCount 1/device <private>) 2026-03-30 14:11:21.934469+0300 0xed Default 0x0 0 0 kernel: (AppleT8110DART) Ignored dart-apcie0 (0xfbfffe18820b0000): DART(DART) error: SID 2 PTE invalid exception on read of DVA 0x9800 (SEG 0 PTE 0x2) ERROR_SID_SUMMARY 0x00003000 TIME 0x11242d43fd TTE 0xffffffffffffffff AXI_ID 0 We do not have any correlation between machines, usage pattern or installed applications. Uninstalling the network protection features seem to largely fix the issues, even though we have heard of crashes happening even in safe mode or with our network extension disabled from system settings. We weren't able to reproduce internally and it seems to happen completely random on client machines, but often enough to be disrupting. Can you tell us please if this is a known problem and if there's a workaround or what can we do to narrow it down? Thanks.
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2d
sysextd: "no policy, cannot allow apps outside /Applications" - NEFilterDataProvider system extension on macOS 26
I'm developing a macOS security tool using NEFilterDataProvider as a system extension. On macOS 26 beta (25E241), sysextd consistently rejects my extension with: sysextd: no policy, cannot allow apps outside /Applications Configuration: App installed in /Applications/ Signed with Developer ID Application (693DSH8GN5) Entitlement: com.apple.developer.networking.networkextension = content-filter-provider com.apple.developer.system-extension.install = true Developer Mode enabled on test machine Comparison with Little Snitch: Little Snitch runs correctly on the same machine. Key differences I found: Little Snitch uses content-filter-provider-systemextension instead of content-filter-provider Little Snitch has com.apple.security.app-sandbox = false Both signed with Developer ID Application When I switch to content-filter-provider-systemextension, Xcode rejects every provisioning profile because none match that entitlement value, and the Developer Portal doesn't expose fine-grained control over the Network Extensions array values. Questions Is content-filter-provider-systemextension the correct entitlement for system extensions on macOS 26? How should the provisioning profile be configured to support it? Is there a known sysextd issue on macOS 26 beta causing this regardless of configuration? Is there - somewhere! - a guide on how to build such an extension? Thanks in advance for your help.
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2w
How to use DNSServiceReconfirmRecord?
TL;DR: How does one use DNSServiceReconfirmRecord() to invalidate mDNS state of a device that's gone offline? I'm using the DNSServiceDiscovery API (dns_sd.h) for a local P2P service. The problem I'm trying to solve is how to deal with a peer that abruptly loses connectivity, i.e. by turning off WiFi or simply by moving out of range or otherwise losing connectivity. In this situation there is of course no notification that the peer device has gone offline; it simply stops sending any packets. After my own timeout mechanism determines the peer is not responding, I mark it as offline in my own data structures. The problem is how to discover when/if it comes back online later. My DNSServiceBrowse callback won't be invoked because mDNS doesn't know the device went offline in the first place. I am trying to use DNSServiceReconfirmRecord, which appears to be for exactly this use case -- "Instruct the daemon to verify the validity of a resource record that appears to be out of date (e.g. because TCP connection to a service's target failed.)" However my attempts always return a BadReference error (-65541). The function requires me to pass a DNS record, and the only one I know is the TXT record; perhaps it needs a different one? Which, and how would I get it? Thanks!
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7
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197
Activity
Feb ’26
Stumped by URLSession behaviour I don't understand...
I have an app that has been using the following code to down load audio files: if let url = URL(string: episode.fetchPath()) { var request = URLRequest(url: url) request.httpMethod = "get" let task = session.downloadTask(with: request) And then the following completionHandler code: func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) { try FileManager.default.moveItem(at: location, to: localUrl) In the spirit of modernization, I'm trying to update this code to use async await: var request = URLRequest(url: url) request.httpMethod = "get" let (data, response) = try await URLSession.shared.data(for: request) try data.write(to: localUrl, options: [.atomicWrite, .completeFileProtection]) Both these code paths use the same url value. Both return the same Data blobs (they return the same hash value) Unfortunately the second code path (using await) introduces a problem. When the audio is playing and the iPhone goes to sleep, after 15 seconds, the audio stops. This problem does not occur when running the first code (using the didFinish completion handler) Same data, stored in the same URL, but using different URLSession calls. I would like to use async/await and not have to experience the audio ending after just 15 seconds of the device screen being asleep. any guidance greatly appreciated.
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7
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638
Activity
Jan ’26
Network Framework: Choosing Interface Types for Browsing/ Advertising
I am using Network framework for connecting two iPad devices that are connected through LAN and has Wifi enabled. I have enabled peerToPeerIncluded. I would like to understand how the framework chooses the interface types for browsing and discovering devices. When I start a browser with browser.run or listener.run, does the browser and advertiser browse and listen on all available interface types? My concern is that if it does in only one interface, Is there a chance that the browser is browsing in one interface(Lets say WiredEthernet) and the listener is listening on another interface(Lets say AWDL) and they dont discover?
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4
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178
Activity
Mar ’26
Network Framework peer to peer limitations
Hi all, We've been exploring the capabilities of the Network.framework for peer-to-peer communication and have run into some behavior that we haven't been able to fully explain with the existing documentation. In our tests, we’re working with 12 iOS devices, all disconnected from Wi-Fi to force communication over Apple Wireless Direct Link (AWDL). While using the Network.framework to create peer-to-peer connections, we observed that the number of connected peers never exceeded 8, despite all 12 devices being active and configured identically. Some questions we’re hoping to get clarification or discussion on: Is there a known upper limit to the number of peer-to-peer connections supported via AWDL? Are there conditions under which the framework or system limits or throttles visible peers? Does AWDL behavior vary by hardware model, iOS version, or backgrounding state of the app? Is there any official documentation or guidance around peer discovery or connection limits when using NWBrowser and NWConnection in a peer-to-peer context? We’d appreciate any insights from the Apple engineering team or other developers who have worked with larger peer groups using Network.framework in peer-to-peer mode.
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4
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8
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250
Activity
May ’25
MultiPeer Connectivity: Device discovery succeeds but handshake fails when off-network
Hi, I am building an app that depends on multiple iOS devices connecting to a designated "coordinator" iOS device. I am using MPC, and it works great when the devices are connected to the same WiFi AP, with virtually 100% connection success. My definition of success is a near instant detection of available devices, >95% connection success rate, and a stable ongoing connection with no unexpected disconnects. The issue arises when the devices are not connected to the same WiFi network (or connected to no network with WiFi and bluetooth still on). Devices detect each other immediately, but when initiating a connection, both devices initiate a handshake, but the connection is not successful. In the few times where the connection succeeds, the connection quality is high, stable, and doesn't drop. Is this a known limitation of the framework? Could I be doing something wrong in my implementation?
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1
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237
Activity
Dec ’25
URLSessionDownloadTaskDelegate functions not called when using URLSession.download(for:), but works when using URLSession.downloadTask(with:)
I'm struggling to understand why the async-await version of URLSession download task APIs do not call the delegate functions, whereas the old non-async version that returns a reference to the download task works just fine. Here is my sample code: class DownloadDelegate: NSObject, URLSessionDownloadDelegate { func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) { // This only prints the percentage of the download progress. let calculatedProgress = Float(totalBytesWritten) / Float(totalBytesExpectedToWrite) let formatter = NumberFormatter() formatter.numberStyle = .percent print(formatter.string(from: NSNumber(value: calculatedProgress))!) } } // Here's the VC. final class DownloadsViewController: UIViewController { private let url = URL(string: "https://pixabay.com/get/g0b9fa2936ff6a5078ea607398665e8151fc0c10df7db5c093e543314b883755ecd43eda2b7b5178a7e613a35541be6486885fb4a55d0777ba949aedccc807d8c_1280.jpg")! private let delegate = DownloadDelegate() private lazy var session = URLSession(configuration: .default, delegate: delegate, delegateQueue: nil) // for the async-await version private var task: Task&lt;Void, Never&gt;? // for the old version private var downloadTask: URLSessionDownloadTask? override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) task?.cancel() task = nil task = Task { let (_, _) = try! await session.download(for: URLRequest(url: url)) self.task = nil } // If I uncomment this, the progress listener delegate function above is called. // downloadTask?.cancel() // downloadTask = nil // downloadTask = session.downloadTask(with: URLRequest(url: url)) // downloadTask?.resume() } } What am I missing here?
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5
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2.1k
Activity
May ’25
Network issues in macOS 26.4 (25E5218f)
Since updating to macOS 26.4 developerbeta 2 I've been getting full loss of dns resolution. I am not running a VPN or any network extensions that I am aware of. I'm not sure how to report this in the feedback utility as I cannot find an appropriate category for it. Happy to file it if someone can give an appropriate suggestion - the closest I could see was Wi-Fi but that wanted Wi-Fi logs for the issue, which I do not believe to be needed as this is not a Wi-Fi connectivity issue. Running dig example.com +short nslookup example.com ping example.com Gives the following output 104.18.27.120 104.18.26.120 Server: 10.0.1.1 Address: 10.0.1.1#53 \ Non-authoritative answer: Name: example.com Address: 104.18.26.120 Name: example.com Address: 104.18.27.120 \ ping: cannot resolve example.com: Unknown host This shows it's not an issue with my local network and that core networking is working, but something in the mDNSResponder/dns stack of macOS is failing. This causes all apps/browsers that do not implement their own DNS lookups to fail (Chrome still works). Sometimes the issue clears after running the following commands (for a period), sometimes it does not. A restart always resolves the issue temporarily. sudo killall -9 mDNSResponder sudo killall -9 mDNSResponderHelper sudo dscacheutil -flushcache sudo ifconfig en0 down sudo ifconfig en0 up
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3
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306
Activity
Mar ’26
DTLS Handshake Fails When App Is in Background – Is This an iOS Limitation?
Hello, We are facing an issue with performing a DTLS handshake when our iOS application is in the background. Our app (Vocera Collaboration Suite – VCS) uses secure DTLS-encrypted communication for incoming VoIP calls. Problem Summary: When the app is in the background and a VoIP PushKit notification arrives, we attempt to establish a DTLS handshake over our existing socket. However, the handshake consistently fails unless the app is already in the foreground. Once the app is foregrounded, the same DTLS handshake logic succeeds immediately. Key Questions: Is performing a DTLS handshake while the app is in the background technically supported by iOS? Or is this an OS-level limitation by design? If not supported, what is the Apple-recommended alternative to establish secure DTLS communication for VoIP flows without bringing the app to the foreground? Any guidance or clarification from Apple engineers or anyone who has solved a similar problem would be greatly appreciated. Thank you.
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5
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367
Activity
Feb ’26
Local network access is blocked when two almost identical apps are installed
We are developing an enterprise app that connects to a local server. It uses simple URLSessions. There is a view in the app where you enter the server url (IP address) and a connection check is made. iOS asks for permission to access the local network. Everything works. If the server is reachable, the connection info is saved. Recently we encountered a very strange issue: We also have a beta version of this app. If we first install the normal version on a device, enter the server IP, save, and then install the beta version and do the same there: It does not get a connection (it waits for the timeout). The strange part is: If I try to configure the connection in the normal version again, it also does not work, it just waits for the timeout. The really strange part: When I delete the beta version, while the normal version is waiting for its connection, the connection succeeds immediately. Both versions have a different display name, bundle id. I also tried using a device that is not in our MDM: same problem. Even the iOS version seems to have no impact: I tried on iOS 15, 18 and 26. Is there an explanation and hopefully also a solution to this problem?
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2
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73
Activity
Dec ’25
NetworkConnection throws EINVAL when receiving ping/pong control frames
Summary NetworkConnection<WebSocket> in iOS 26 Network framework throws POSIXErrorCode(rawValue: 22): Invalid argument when receiving WebSocket ping (opcode 9) or pong (opcode 10) control frames. This prevents proper WebSocket keep-alive functionality. Environment iOS 26.0 (Simulator) macOS 26.1 Xcode 26.0 Note: This issue was initially discovered on iOS 26 Simulator. The same behavior was confirmed on macOS 26, suggesting a shared bug in the Network framework. The attached sample code is for macOS for easier reproduction. Description When using the new NetworkConnection<WebSocket> API introduced in iOS 26 or macOS 26, the receive() method throws EINVAL error whenever a ping or pong control frame is received from the server. This is a critical issue because: WebSocket servers commonly send ping frames to keep connections alive Clients send ping frames to verify connection health The receive callback never receives the ping/pong frame - the error occurs before the frame reaches user code Steps to Reproduce Create a WebSocket connection to any server that supports ping/pong (e.g., wss://echo.websocket.org): import Foundation import Network // MARK: - WebSocket Ping/Pong EINVAL Bug Reproduction // This sample demonstrates that NetworkConnection<WebSocket> throws EINVAL // when receiving ping or pong control frames. @main struct WebSocketPingPongBug { static func main() async { print("=== WebSocket Ping/Pong EINVAL Bug Reproduction ===\n") do { try await testPingPong() } catch { print("Test failed with error: \(error)") } } static func testPingPong() async throws { let host = "echo.websocket.org" let port: UInt16 = 443 print("Connecting to wss://\(host)...") let endpoint = NWEndpoint.hostPort( host: NWEndpoint.Host(host), port: NWEndpoint.Port(rawValue: port)! ) try await withNetworkConnection(to: endpoint, using: { WebSocket { TLS { TCP() } } }) { connection in print("Connected!\n") // Start receive loop in background let receiveTask = Task { var messageCount = 0 while !Task.isCancelled { do { let (data, metadata) = try await connection.receive() messageCount += 1 print("[\(messageCount)] Received frame - opcode: \(metadata.opcode)") if let text = String(data: data, encoding: .utf8) { print("[\(messageCount)] Content: \(text)") } else { print("[\(messageCount)] Binary data: \(data.count) bytes") } } catch let error as NWError { if case .posix(let code) = error, code == .EINVAL { print("❌ EINVAL error occurred! (POSIXErrorCode 22: Invalid argument)") print(" This is the bug - ping/pong frame caused EINVAL") // Continue to demonstrate workaround continue } print("Receive error: \(error)") break } catch { print("Receive error: \(error)") break } } } // Wait for initial message from server try await Task.sleep(for: .seconds(2)) // Test 1: Send text message (should work) print("\n--- Test 1: Sending text message ---") try await connection.send("Hello, WebSocket!") print("✅ Text message sent") try await Task.sleep(for: .seconds(1)) // Test 2: Send ping (pong response will cause EINVAL) print("\n--- Test 2: Sending ping frame ---") print("Expecting EINVAL when pong is received...") let pingMetadata = NWProtocolWebSocket.Metadata(opcode: .ping) try await connection.ping(Data()) { pingMetadata } print("✅ Ping sent, waiting for pong...") // Wait for pong response try await Task.sleep(for: .seconds(2)) // Cleanup receiveTask.cancel() print("\n=== Test Complete ===") print("If you saw 'EINVAL error occurred!' above, the bug is reproduced.") } } } The receive() call fails with error when pong arrives: ❌ EINVAL error occurred! (POSIXErrorCode 22: Invalid argument) Test Results Scenario Result Send/receive text (opcode 1) ✅ OK Client sends ping, receives pong ❌ EINVAL on pong receive Expected Behavior The receive() method should successfully return ping and pong frames, or at minimum, handle them internally without throwing an error. The autoReplyPing option should allow automatic pong responses without disrupting the receive loop. Actual Behavior When a ping or pong control frame is received: The receive() method throws NWError.posix(.EINVAL) The frame never reaches user code (no opcode check is possible) The connection remains valid, but the receive loop is interrupted Workaround Catch the EINVAL error and restart the receive loop: while !Task.isCancelled { do { let received = try await connection.receive() // Process message } catch let error as NWError { if case .posix(let code) = error, code == .EINVAL { // Control frame caused EINVAL, continue receiving continue } throw error } } This workaround allows continued operation but: Cannot distinguish between ping-related EINVAL and other EINVAL errors Cannot access the ping/pong frame content Cannot implement custom ping/pong handling Impact WebSocket connections to servers that send periodic pings will experience repeated EINVAL errors Applications must implement workarounds that may mask other legitimate errors Additional Information Packet capture confirms ping/pong frames are correctly transmitted at the network level The error occurs in the Network framework's internal processing, before reaching user code
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5
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285
Activity
Dec ’25
Wi-Fi Raw Socket Disconnection Issue on iPhone 17 Series
On my iPhone 16 Pro and iPhone 16 Pro Max devices, running iOS 26.0, 26.0.1, and 26.1, Wi-Fi raw socket communication works flawlessly. Even after keeping the connection active for over 40 minutes, there are no disconnections during data transmission. However, on the iPhone 17 and iPhone 17 Pro, the raw socket connection drops within 20 seconds. Once it disconnects, the socket cannot reconnect unless the Wi-Fi module itself is reset. I believe this issue is caused by a bug in the iPhone 17 series’ communication module. I have looked into many cases, and it appears to be related to a bug in the N1 chipset. Are there any possible solutions or workarounds for this issue?
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7
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390
Activity
Mar ’26
Accessory Setup Kit (BLE) not showing multiple options nor the advertising name
I'm developing an application using the accessory setup kit (BLE) on iOS 18+. An important aspect of the connection process is being able to find and choose the correct device. I noticed on iOS 18.2 that I was able to both scroll through the discovered accessories as well as view the advertised name. However, after upgrading to 18.7.2, only a single device is viewable and the advertised name is no longer available. Is there a trigger for this feature that I need to enable or was this "multiple discovery" feature removed? If so, why?
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232
Activity
Oct ’25
After updating to Xcode26, the current SSID can no longer be retrieved
fetchCurrent(completionHandler:) https://developer.apple.com/documentation/networkextension/nehotspotnetwork/fetchcurrent(completionhandler:) The same code works fine in Xcode 16, but when I run the same project in Xcode 26, it doesn't work
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1
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103
Activity
Oct ’25
URL filter app with multiple configurations
Hello, We've been working on an app that uses the new NEUrlFilter API and we've got a question. Currently, the system is designed with the assumption that a single app == usecase == single remote database. But what if we would like to give the user the ability to use different blocklists? For example, the user may want to: Block scam domains Block tracking domains Block adult domains Or any composition of these 3 What should we do to give the user this option? It seems that we could differentiate different databases by using different PIR service hostnames, but that would also mean that we'll have to send several requests for the same usecase but with different PIR service hostnames (and they'll all share the same app bundle ID). Will these requests be accepted then? If not, is there an alternative? PS: By sending a request I mean submitting this form
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1
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159
Activity
Oct ’25
DeviceDiscoveryUI and Bonjour for iOS
I have some confusion around the usage of DeviceDiscoveryUI. The documentation suggests that it is available only on TVOS. But with the recent announcement of WifiAware, it has been used in iOS devices as well. Within DeviceDiscoveryUI, the DevicePicker or the DevicePairingView documentation seems to be available with iOS. Is this just a documentation mistake? Followup - Can I use DeviceDiscoveryUI's DevicePicker/ DevicePairingView to discover devices through Bonjour and then establish a connection through Network framework?
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2
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1
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193
Activity
Oct ’25
Network access blocked by system
I’m building an app on macOS 26.4 with Xcode 26.4. When I build and run my app it started prompting me for network access, which it didn’t do before with Xcode 26. It did that repeatedly, and I had been approving the prompts and the app had been working. Now the app’s network features are not working, and I assume its because its being blocked by macOS, even though I accepted the network requests each time. In System Settings - Privacy and Security - Local Network, the app has many repeated entries, like 20, and all of them are turned on.
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2
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88
Activity
5d
Crash in URLConnectionLoader::loadWithWhatToDo
There are multiple report of crashes on URLConnectionLoader::loadWithWhatToDo. The crashed thread in the stack traces pointing to calls inside CFNetwork which seems to be internal library in iOS. The crash has happened quite a while already (but we cannot detect when the crash started to occur) and impacted multiple iOS versions recorded from iOS 15.4 to 18.4.1 that was recorded in Xcode crash report organizer so far. Unfortunately, we have no idea on how to reproduce it yet but the crash keeps on increasing and affect more on iOS 18 users (which makes sense because many people updated their iOS to the newer version) and we haven’t found any clue on what actually happened and how to fix it on the crash reports. What we understand is it seems to come from a network request that happened to trigger the crash but we need more information on what (condition) actually cause it and how to solve it. Hereby, I attach sample crash report for both iOS 15 and 18. I also have submitted a report (that include more crash reports) with number: FB17775979. Will appreciate any insight regarding this issue and any resolution that we can do to avoid it. iOS 15.crash iOS 18.crash
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10
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726
Activity
Jan ’26
`NEProxySettings.matchDomains` / `exceptionList` not working as expected in `NEPacketTunnelProvider` (domain-scoped proxy not applied, and exceptions not bypassed)
I’m working on an iOS Network Extension where a NEPacketTunnelProviderconfigures a local HTTP/HTTPS proxy usingNEPacketTunnelNetworkSettings.proxySettings. Per NEProxySettings.exceptionList docs: If the destination host name of an HTTP connection matches one of these patterns then the proxy settings will not be used for the connection. However, I’m seeing two distinct issues: Issue A (exception bypass not working): HTTPS traffic to a host that matches exceptionList still reaches the proxy. Issue B (domain-scoped proxy not applied): When matchDomains is set to match a specific domain (example: ["googlevideo.com"]), I still observe its traffic in some apps is not proxied. If I remove the domain from matchDomains, the same traffic is proxied. Environment OS: iOS (reproduced with 26.4 and other versions) Devices: Reproduced with several iPhones (likely iPads as well) Xcode: 26.3 Extension: NEPacketTunnelProvider Minimal Repro (code) This is the minimal configuration. Toggle between CONFIG A / CONFIG B to reproduce each issue. import NetworkExtension final class PacketTunnelProvider: NEPacketTunnelProvider { override func startTunnel( options: [String : NSObject]? = nil, completionHandler: @escaping (Error?) -> Void ) { let proxyPort = 12345 // proxy listening port let settings = NEPacketTunnelNetworkSettings(tunnelRemoteAddress: "8.8.8.8") let proxySettings = NEProxySettings() proxySettings.httpEnabled = true proxySettings.httpsEnabled = true proxySettings.httpServer = NEProxyServer(address: "1.2.3.4", port: proxyPort) // proxy listening address proxySettings.httpsServer = NEProxyServer(address: "1.2.3.4", port: proxyPort) // proxy listening address // CONFIG A: proxy all domains, but exclude some domains // proxySettings.matchDomains can be set to match all domains // proxySettings.exceptionList = ["*.cdninstagram.com", "cdninstagram.com"] // CONFIG B: proxy only a specific domain // proxySettings.matchDomains = ["googlevideo.com"] settings.proxySettings = proxySettings setTunnelNetworkSettings(settings) { error in completionHandler(error) } } } Repro steps Issue A (exceptionList bypass not working) Enable the VPN configuration and start the tunnel with CONFIG A (exceptionList = ["*.cdninstagram.com", "cdninstagram.com"]). Open the Instagram app to trigger HTTPS connections to *.cdninstagram.com Inspect proxy logs: cdninstagram.com traffic is still received by the proxy. Safari comparison: If I access URLs that trigger the same *.cdninstagram.com hosts from Safari, it can behave as expected. When the traffic is triggered from the Instagram app, the excluded host still reaches the proxy as CONNECT, which is unexpected. Issue B (matchDomains not applied for YouTube traffic) Start the tunnel with CONFIG B (matchDomains = ["googlevideo.com"]). Open the YouTube app and start playing a video (traffic typically targets *.googlevideo.com). Inspect proxy logs: googlevideo.com traffic is not received by the proxy. Remove the host from matchDomains and observe that googlevideo.com traffic is received by the proxy. Safari comparison: If I access a googlevideo.com host from Safari while matchDomains = ["googlevideo.com"], it behaves as expected (proxied). In contrast, the YouTube app’s googlevideo.com traffic is not proxied unless I match all domains. Expected Issue A Connections to *.cdninstagram.com in the Instagram app should not use the proxy and should not reach the local proxy server. Issue B With matchDomains = ["googlevideo.com"], traffic to *.googlevideo.com (YouTube video traffic) should be proxied and therefore reach the local proxy. Actual Issue A The local proxy still receives the request as: CONNECT scontent-mad1-1.cdninstagram.com:443 HTTP/1.1 So the bypass does not happen. Issue B With matchDomains = ["googlevideo.com"], I still observe googlevideo.com traffic in the YouTube app that is not delivered to the proxy. When all traffic is proxied, the same traffic is delivered to the proxy.
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94
Activity
1w
Kernel panics on M5 devices with network extension
Hello, We have a security solution which intercepts network traffic for inspection using a combination of Transparent Proxy Provider and Content filter. Lately we are seeing reports from the market that on M5 Macbooks and A18 Neos the system will kernel panic using our solution, even though it never happens on M1-M4 and no significant code changes were made in the mean time. All crashes seem to be related to an internal double free in the kernel: panic(cpu 0 caller 0xfffffe003bb68224): skmem_slab_free_locked: attempt to free invalid or already-freed obj 0xf2fffe29e15f2400 on skm 0xf6fffe2518aaa200 @skmem_slab.c:646 Debugger message: panic Memory ID: 0xff OS release type: User OS version: 25D2128 Kernel version: Darwin Kernel Version 25.3.0: Wed Jan 28 20:54:38 PST 2026; root:xnu-12377.91.3~2/RELEASE_ARM64_T6050 Additionally, from further log inspection, before panics we find some weird kernel messages which seem to be related to some DMA operations gone wrong in the network driver on some machines: 2026-03-30 14:11:21.779124+0300 0x30f2 Default 0x0 873 0 Arc: (Network) [com.apple.network:connection] [C9.1.1.1 IPv4#e5b4bb04:443 in_progress socket-flow (satisfied (Path is satisfied), interface: en0[802.11], ipv4, ipv6, dns, uses wifi, flow divert agg: 1, LQM: good)] event: flow:start_connect @0.075s 2026-03-30 14:11:21.780015+0300 0x1894 Default 0x0 0 0 kernel: (402262746): No more valid control units, disabling flow divert 2026-03-30 14:11:21.780017+0300 0x1894 Default 0x0 0 0 kernel: (402262746): Skipped all flow divert services, disabling flow divert 2026-03-30 14:11:21.780102+0300 0x1894 Default 0x0 0 0 kernel: SK[2]: flow_entry_alloc fe "0 proc kernel_task(0)Arc nx_port 1 flow_uuid D46E230E-B826-4E0A-8C59-4C4C8BF6AA60 flags 0x14120<CONNECTED,QOS_MARKING,EXT_PORT,EXT_FLOWID> ipver=4,src=<IPv4-redacted>.49703,dst=<IPv4-redacted>.443,proto=0x06 mask=0x0000003f,hash=0x04e0a750 tp_proto=0x06" 2026-03-30 14:11:21.780194+0300 0x1894 Default 0x0 0 0 kernel: tcp connect outgoing: [<IPv4-redacted>:49703<-><IPv4-redacted>:443] interface: en0 (skipped: 0) so_gencnt: 14634 t_state: SYN_SENT process: Arc:873 SYN in/out: 0/1 bytes in/out: 0/0 pkts in/out: 0/0 rtt: 0.0 ms rttvar: 250.0 ms base_rtt: 0 ms error: 0 so_error: 0 svc/tc: 0 flow: 0x9878386f 2026-03-30 14:11:21.934431+0300 0xed Default 0x0 0 0 kernel: Hit error condition (not panicking as we're in error handler): t8110dart <private> (dart-apcie0): invalid SID 2 TTBR access: level 1 table_index 0 page_offset 0x2 2026-03-30 14:11:21.934432+0300 0xed Default 0x0 0 0 kernel: [ 73.511690]: arm_cpu_init(): cpu 6 online 2026-03-30 14:11:21.934441+0300 0xed Default 0x0 0 0 kernel: [ 73.511696]: arm_cpu_init(): cpu 9 online 2026-03-30 14:11:21.934441+0300 0xed Default 0x0 0 0 kernel: [ 73.569033]: arm_cpu_init(): cpu 6 online 2026-03-30 14:11:21.934441+0300 0xed Default 0x0 0 0 kernel: [ 73.569038]: arm_cpu_init(): cpu 9 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.577453]: arm_cpu_init(): cpu 7 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.586328]: arm_cpu_init(): cpu 5 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.586332]: arm_cpu_init(): cpu 8 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.621392]: (dart-apcie0) AppleT8110DART::_fatalException: dart-apcie0 (<ptr>): DART DART SID exception ERROR_SID_SUMMARY 0x00003000 ERROR_ADDRESS 0x0000000000009800 2026-03-30 14:11:21.934443+0300 0xed Default 0x0 0 0 kernel: [ 73.621397]: Hit error condition (not panicking as we're in error handler): 2026-03-30 14:11:21.934443+0300 0xed Default 0x0 0 0 kernel: t8110dart <ptr> (dart-apcie0): invalid SID 2 TTBR access: level 1 table_index 0 page_offset 0x2Expect a `deadbeef` in the error messages below 2026-03-30 14:11:21.934452+0300 0xed Default 0x0 0 0 kernel: Expect a `deadbeef` in the error messages below 2026-03-30 14:11:21.934456+0300 0xed Default 0x0 0 0 kernel: (AppleEmbeddedPCIE) apcie[0:centauri-control]::_dartErrorHandler() InvalidPTE caused by read from address 0x9800 by SID 2 (RID 2:0:1/useCount 1/device <private>) 2026-03-30 14:11:21.934469+0300 0xed Default 0x0 0 0 kernel: (AppleT8110DART) Ignored dart-apcie0 (0xfbfffe18820b0000): DART(DART) error: SID 2 PTE invalid exception on read of DVA 0x9800 (SEG 0 PTE 0x2) ERROR_SID_SUMMARY 0x00003000 TIME 0x11242d43fd TTE 0xffffffffffffffff AXI_ID 0 We do not have any correlation between machines, usage pattern or installed applications. Uninstalling the network protection features seem to largely fix the issues, even though we have heard of crashes happening even in safe mode or with our network extension disabled from system settings. We weren't able to reproduce internally and it seems to happen completely random on client machines, but often enough to be disrupting. Can you tell us please if this is a known problem and if there's a workaround or what can we do to narrow it down? Thanks.
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sysextd: "no policy, cannot allow apps outside /Applications" - NEFilterDataProvider system extension on macOS 26
I'm developing a macOS security tool using NEFilterDataProvider as a system extension. On macOS 26 beta (25E241), sysextd consistently rejects my extension with: sysextd: no policy, cannot allow apps outside /Applications Configuration: App installed in /Applications/ Signed with Developer ID Application (693DSH8GN5) Entitlement: com.apple.developer.networking.networkextension = content-filter-provider com.apple.developer.system-extension.install = true Developer Mode enabled on test machine Comparison with Little Snitch: Little Snitch runs correctly on the same machine. Key differences I found: Little Snitch uses content-filter-provider-systemextension instead of content-filter-provider Little Snitch has com.apple.security.app-sandbox = false Both signed with Developer ID Application When I switch to content-filter-provider-systemextension, Xcode rejects every provisioning profile because none match that entitlement value, and the Developer Portal doesn't expose fine-grained control over the Network Extensions array values. Questions Is content-filter-provider-systemextension the correct entitlement for system extensions on macOS 26? How should the provisioning profile be configured to support it? Is there a known sysextd issue on macOS 26 beta causing this regardless of configuration? Is there - somewhere! - a guide on how to build such an extension? Thanks in advance for your help.
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