General: Forums subtopic: App & System Services > Networking TN3151 Choosing the right networking API Networking Overview document — Despite the fact that this is in the archive, this is still really useful. TLS for App Developers forums post Choosing a Network Debugging Tool documentation WWDC 2019 Session 712 Advances in Networking, Part 1 — This explains the concept of constrained networking, which is Apple’s preferred solution to questions like How do I check whether I’m on Wi-Fi? TN3135 Low-level networking on watchOS TN3179 Understanding local network privacy Adapt to changing network conditions tech talk Understanding Also-Ran Connections forums post Extra-ordinary Networking forums post Foundation networking: Forums tags: Foundation, CFNetwork URL Loading System documentation — NSURLSession, or URLSession in Swift, is the recommended API for HTTP[S] on Apple platforms. Moving to Fewer, Larger Transfers forums post Testing Background Session Code forums post Network framework: Forums tag: Network Network framework documentation — Network framework is the recommended API for TCP, UDP, and QUIC on Apple platforms. Building a custom peer-to-peer protocol sample code (aka TicTacToe) Implementing netcat with Network Framework sample code (aka nwcat) Configuring a Wi-Fi accessory to join a network sample code Moving from Multipeer Connectivity to Network Framework forums post NWEndpoint History and Advice forums post Network Extension (including Wi-Fi on iOS): See Network Extension Resources Wi-Fi Fundamentals TN3111 iOS Wi-Fi API overview Wi-Fi Aware framework documentation Wi-Fi on macOS: Forums tag: Core WLAN Core WLAN framework documentation Wi-Fi Fundamentals Secure networking: Forums tags: Security Apple Platform Security support document Preventing Insecure Network Connections documentation — This is all about App Transport Security (ATS). WWDC 2017 Session 701 Your Apps and Evolving Network Security Standards [1] — This is generally interesting, but the section starting at 17:40 is, AFAIK, the best information from Apple about how certificate revocation works on modern systems. Available trusted root certificates for Apple operating systems support article Requirements for trusted certificates in iOS 13 and macOS 10.15 support article About upcoming limits on trusted certificates support article Apple’s Certificate Transparency policy support article What’s new for enterprise in iOS 18 support article — This discusses new key usage requirements. Technote 2232 HTTPS Server Trust Evaluation Technote 2326 Creating Certificates for TLS Testing QA1948 HTTPS and Test Servers Miscellaneous: More network-related forums tags: 5G, QUIC, Bonjour On FTP forums post Using the Multicast Networking Additional Capability forums post Investigating Network Latency Problems forums post WirelessInsights framework documentation iOS Network Signal Strength forums post Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" [1] This video is no longer available from Apple, but the URL should help you locate other sources of this info.

Hi! We have created an app that communicates with devices over BLE, and it is currently out in Testflight. It works as expected for almost everyone, but for some users we get a strange behaviour. We start by scanning for devices with scanForPeripherals(withServices:options:), then connect, and finally initiate pairing by subscribing and writing to a pair of characteristics, which both require encryption. The issue is that for these users, the following code: func peripheral( _ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error? ) { guard error == nil else { LogManager.shared.log( "❌ Error discovering characteristics: \(error!)" ) return } for characteristic in service.characteristics ?? [] { if characteristic.uuid == controlPointUUID { controlPointCharacteristic = characteristic LogManager.shared.debugLog( "Control Point characteristic found." ) } else if characteristic.uuid == statusUUID { statusCharacteristic = characteristic LogManager.shared.debugLog("Notify characteristic found.") } } if statusCharacteristic != nil { LogManager.shared.debugLog("Call Set notify.") peripheral.setNotifyValue(true, for: statusCharacteristic!) } } func peripheral( _ peripheral: CBPeripheral, didUpdateNotificationStateFor characteristic: CBCharacteristic, error: Error? ) { if error != nil { LogManager.shared.log( "❌ Failed to subscribe to \(characteristic.uuid): \(error.debugDescription)" ) produces this error: > > [22:31:34.632] ❌ Failed to subscribe to F1D0FFF2-DEAA-ECEE-B42F-C9BA7ED623BB: Optional(Error Domain=CBATTErrorDomain Code=15 "Encryption is insufficient." UserInfo={NSLocalizedDescription=Encryption is insufficient.}) So in essence, we can't perform pairing and enable encryption, because we have insufficient encryption. I know that the system caches some key material after pairing. When I do "Forget device" and then pair again, I don't need to put my device in pairing mode for the pairing pin to appear, which is not the case for devices that have not been paired before. Given that I can't reproduce the problem locally, it's hard to debug using the console. What I've been trying to do is figure out how to reset Bluetooth, which should hopefully remove old keys and whatever else might be there. The top hit when searching for 'clear corebluetooth cache macos' is on stackexchange, and writes: Turn off Bluetooth Delete com.apple.Bluetooth.plist from /Library/Preferences Delete files named com.apple.Bluetooth.somehexuuidstuff.plist from ~/Library/Preferences/ByHost (note that this is the user preference folder, not the system one) Turn on Bluetooth The answer is from December 2013, so it's not surpising that things don't work out of the box, but anyways: My ByHost folder does not contain any plist files with Bluetooth in them, and deleting the one in /Library/Preferences did not do anything, and judging from the content, it does not contain anything valuable. I have tried "sudo grep -r 'Bluetooth' ." in both /Library/Preferences/ and ~/Library/Preferences/ and looked at the resulting hits, but I can't seem to find anything meaningful. As a sidenote, does anyone know what is going on with Apple's entitlement service? We applied for an entitlement in August and have yet to receive a response.

We've received logs and have spuriously reproduced the following behavior: calls to setTunnelNetworkSettings completing with NETunnelProviderError where the code is networkSettingsInvalid, and the error domain string is empty. After subsequent calls to setTunnelNetworkSettings, the tunnel is stopped via the userInitiated stop reason within around 1 second from the first failure. This happens after a number of successful calls to setTunnelNetworkSettings have been made in the lifetime of a given packet tunnel process. We can confirm that no user ever initiates the disconnection. We can confirm that the only significant changes between the different calls to setTunnelNetworkSettings are that the parameters contain different private IPs for the tunnel settings - the routes and DNS settings remain the same. In our limited testing, it seems that we can replicate the behavior we're observing by removing the VPN profile while the tunnel is up. However, we are certain the same behavior happens under other circumstances without any user interaction. Is this what memory starvation looks like? Or is this something else? Our main concern is that the tunnel is killed and it is not brought back up even though our profile is set to be on-demand. It's difficult to give any promises about leaks to our users if the tunnel can be killed at any point and not be brought back. The spurious disconnections are a security issue for our app, we'd like to know if there's anything we can do differently so that this does not happen. We tried to get DTS, but given that we have no way to reproduce this issue with a minimal project. But we can reproduce the behavior (kill the tunnel by removing it's profile) from a minimal Xcode project, is that considered good enough for a reproduction?

For a long time our app had this creation of a URLRequest: var urlRequest = URLRequest(url: url, cachePolicy: .reloadIgnoringLocalAndRemoteCacheData, timeoutInterval: timeout) But since iOS 26 was released we started to get crashes in this call. It is created on a background thread. Thread 10 Crashed: 0 libsystem_malloc.dylib 0x00000001920e309c _xzm_xzone_malloc_freelist_outlined + 864 (xzone_malloc.c:1869) 1 libswiftCore.dylib 0x0000000184030360 swift::swift_slowAllocTyped(unsigned long, unsigned long, unsigned long long) + 56 (Heap.cpp:110) 2 libswiftCore.dylib 0x0000000184030754 swift_allocObject + 136 (HeapObject.cpp:245) 3 Foundation 0x00000001845dab9c specialized _ArrayBuffer._consumeAndCreateNew(bufferIsUnique:minimumCapacity:growForAppend:) + 120 4 Foundation 0x00000001845daa58 specialized static _SwiftURL._makeCFURL(from:baseURL:) + 2288 (URL_Swift.swift:1192) 5 Foundation 0x00000001845da118 closure #1 in _SwiftURL._nsurl.getter + 112 (URL_Swift.swift:64) 6 Foundation 0x00000001845da160 partial apply for closure #1 in _SwiftURL._nsurl.getter + 20 (<compiler-generated>:0) 7 Foundation 0x00000001845da0a0 closure #1 in _SwiftURL._nsurl.getterpartial apply + 16 8 Foundation 0x00000001845d9a6c protocol witness for _URLProtocol.bridgeToNSURL() in conformance _SwiftURL + 196 (<compiler-generated>:974) 9 Foundation 0x000000018470f31c URLRequest.init(url:cachePolicy:timeoutInterval:) + 92 (URLRequest.swift:44)# Live For Studio Any idea if this crash is caused by our code or if it is a known problem in iOS 26? I have attached one of the crash reports from Xcode: 2025-10-08_10-13-45.1128_+0200-8acf1536892bf0576f963e1534419cd29e6e10b8.crash

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.

Hi there, We have been trying to set up URL filtering for our app but have run into a wall with generating the bloom filter. Firstly, some context about our set up: OHTTP handlers Uses pre-warmed lambdas to expose the gateway and the configs endpoints using the javascript libary referenced here - https://developers.cloudflare.com/privacy-gateway/get-started/#resources Status = untested We have not yet got access to Apples relay servers PIR service We run the PIR service through AWS ECS behind an ALB The container clones the following repo https://github.com/apple/swift-homomorphic-encryption, outside of config changes, we do not have any custom functionality Status = working From the logs, everything seems to be working here because it is responding to queries when they are sent, and never blocking anything it shouldn’t Bloom filter generation We generate a bloom filter from the following url list: https://example.com http://example.com example.com Then we put the result into the url filtering example application from here - https://developer.apple.com/documentation/networkextension/filtering-traffic-by-url The info generated from the above URLs is: { "bits": 44, "hashes": 11, "seed": 2538058380, "content": "m+yLyZ4O" } Status = broken We think this is broken because we are getting requests to our PIR server for every single website we visit We would have expected to only receive requests to the PIR server when going to example.com because it’s in our block list It’s possible that behind the scenes Apple runs sporadically makes requests regardless of the bloom filter result, but that isn’t what we’d expect We are generating our bloom filter in the following way: We double hash the URL using fnv1a for the first, and murmurhash3 for the second hashTwice(value: any, seed?: any): any { return { first: Number(fnv1a(value, { size: 32 })), second: murmurhash3(value, seed), }; } We calculate the index positions from the following function/formula , as seen in https://github.com/ameshkov/swift-bloom/blob/master/Sources/BloomFilter/BloomFilter.swift#L96 doubleHashing(n: number, hashA: number, hashB: number, size: number): number { return Math.abs((hashA + n * hashB) % size); } Questions: What hashing algorithms are used and can you link an implementation that you know is compatible with Apple’s? How are the index positions calculated from the iteration number, the size, and the hash results? There was mention of a tool for generating a bloom filter that could be used for Apple’s URL filtering implementation, when can we expect the release of this tool?

We have a Java application built for macOS. On the first launch, the application prompts the user to allow local network access. We've correctly added the NSLocalNetworkUsageDescription key to the Info.plist, and the provided description appears in the system prompt. After the user grants permission, the application can successfully connect to a local server using its hostname. However, the issue arises after the system is rebooted. When the application is launched again, macOS does not prompt for local network access a second time—which is expected, as the permission was already granted. Despite this, the application is unable to connect to the local server. It appears the previously granted permission is being ignored after a reboot. A temporary workaround is to manually toggle the Local Network permission off and back on via System Settings &gt; Privacy &amp; Security, which restores connectivity—until the next reboot. This behavior is highly disruptive, both for us and for a significant number of our users. We can reproduce this on multiple systems... The issues started from macOS Sequoia 15.0 By opening the application bundle using "Show Package Contents," we can launch the application via "JavaAppLauncher" without any issues. Once started, the application is able to connect to our server over the local network. This seems to bypass the granted permissions? "JavaAppLauncher" is also been used in our Info.plist file

I'm trying to use ThreadNetwork API to manage TheradNetworks on device (following this documentation: https://developer.apple.com/documentation/threadnetwork/), but while some functions on THClient work (such as getPreferedNetwork), most don't (storeCredentials, retrieveAllCredentials). When calling these functions I get the following warning/error: Client: -[THClient getConnectionEntitlementValidity]_block_invoke - Error: -[THClient storeCredentialsForBorderAgent:activeOperationalDataSet:completion:]_block_invoke:701: - Error: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service with pid 414 named com.apple.ThreadNetwork.xpc was invalidated from this process." UserInfo={NSDebugDescription=The connection to service with pid 414 named com.apple.ThreadNetwork.xpc was invalidated from this process.} Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service with pid 414 named com.apple.ThreadNetwork.xpc was invalidated from this process." UserInfo={NSDebugDescription=The connection to service with pid 414 named com.apple.ThreadNetwork.xpc was invalidated from this process.} Failed to store Thread credentials: Couldn’t communicate with a helper application. STEPS TO REPRODUCE Create new project Add Thread Network capability via Xcode UI (com.apple.developer.networking.manage-thread-network-credentials) Trigger storeCredentials let extendedMacData = "9483C451DC3E".hexadecimal let tlvHex = "0e080000000000010000000300001035060004001fffe002083c66f0dc9ef53f1c0708fdb360c72874da9905104094dce45388fd3d3426e992cbf0697b030d474c2d5332302d6e65773030310102250b04106c9f919a4da9b213764fc83f849381080c0402a0f7f8".hexadecimal // Initialize the THClient let thClient = THClient() // Store the credentials await thClient.storeCredentials(forBorderAgent: extendedMacData!, activeOperationalDataSet: tlvHex!) { error in if let error = error { print(error) print("Failed to store Thread credentials: \(error.localizedDescription)") } else { print("Successfully stored Thread credentials") } } NOTES: I tried with first calling getPreferedNetwork to initiate network permission dialog Tried adding meshcop to bojur services Tried with different release and debug build configurations

I am developing a program on my chip and attempting to establish a connection with the WiFi Aware demo app launched by iOS 26. Currently, I am encountering an issue during the pairing phase. If I am the subscriber of the service and successfully complete the follow-up frame exchange of pairing bootstrapping, I see the PIN code displayed by iOS. Question 1: How should I use this PIN code? Question 2: Subsequently, I need to negotiate keys with iOS through PASN. What should I use as the password for the PASN SAE process? If I am the subscriber of the service and successfully complete the follow-up frame exchange of pairing bootstrapping, I should display the PIN code. Question 3: How do I generate this PIN code? Question 4: Subsequently, I need to negotiate keys with iOS through PASN. What should I use as the password for the PASN SAE process?

Hi all, I have a working macOS (Intel) system extension app that currently uses only a Content Filter (NEFilterDataProvider). I need to capture/log HTTP and HTTPS traffic in plain text, and I understand NETransparentProxyProvider is the right extension type for that. For HTTPS I will need TLS inspection / a MITM proxy — I’m new to that and unsure how complex it will be. For DNS data (in plain text), can I use the same extension, or do I need a separate extension type such as NEPacketTunnelProvider, NEFilterPacketProvider, or NEDNSProxyProvider? Current architecture: Two Xcode targets: MainApp and a SystemExtension target. The SystemExtension target contains multiple network extension types. MainApp ↔ SystemExtension communicate via a bidirectional NSXPC connection. I can already enable two extensions (Content Filter and TransparentProxy). With the NETransparentProxy, I still need to implement HTTPS capture. Questions I’d appreciate help with: Can NETransparentProxy capture the DNS fields I need (dns_hostname, dns_query_type, dns_response_code, dns_answer_number, etc.), or do I need an additional extension type to capture DNS in plain text? If a separate extension is required, is it possible or problematic to include that extension type (Packet Tunnel / DNS Proxy / etc.) in the same SystemExtension Xcode target as the TransparentProxy? Any recommended resources or guidance on TLS inspection / MITM proxy setup for capturing HTTPS logs? There are multiple DNS transport types — am I correct that capturing DNS over UDP (port 53) is not necessarily sufficient? Which DNS types should I plan to handle? I’ve read that TransparentProxy and other extension types (e.g., Packet Tunnel) cannot coexist in the same Xcode target. Is that true? Best approach for delivering logs from multiple extensions to the main app (is it feasible)? Or what’s the best way to capture logs so an external/independent process (or C/C++ daemon) can consume them? Required data to capture (not limited to): All HTTP/HTTPS (request, body, URL, response, etc.) DNS fields: dns_hostname, dns_query_type, dns_response_code, dns_answer_number, and other DNS data — all in plain text. I’ve read various resources but remain unclear which extension(s) to use and whether multiple extension types can be combined in one Xcode target. Please ask if you need more details. Thank you.

This is just an FYI in case someone else runs into this problem. This afternoon (12 Dec 2025), I updated to macOS 26.2 and lost my network. The System Settings' Wi-Fi light was green and said it was connected, but traceroute showed "No route to host". I turned Wi-Fi on & off. I rebooted the Mac. I rebooted the eero network. I switched to tethering to my iPhone. I switched to physical ethernet cable. Nothing worked. Then I remembered I had a beta of an app with a network system extension that was distributed through TestFlight. I deleted the app, and networking came right back. I had this same problem ~2 years ago. Same story: app with network system extension + TestFlight + macOS update = lost network. (My TestFlight build might have expired, but I'm not certain) I don't know if anyone else has had this problem, but I thought I'd share this in case it helps.

I have an app that uses BLE to connect to access doors. Since iOS 26, when it hasn't connected to any doors for a while, it deactivates, whereas in older versions of iOS it continues to work all day without stopping. Has anyone else experienced this? I've found problems with people who have had the same issue since upgrading to the latest version of iOS 26. Is there a known issue with BLE in iOS 26? I haven't found any official information. thnks

Hello, I’m reviewing the open-source mDNSResponder repository and have a question regarding licensing/provenance in mDNSCore/DNSDigest.c file. That file contains an embedded notice stating that parts of the MD5/digest implementation were derived from older OpenSSL sources and therefore include the legacy OpenSSL/SSLeay license text, even though OpenSSL itself is now Apache-2.0 starting from version 3.0. The legacy OpenSSL/SSLeay license is widely understood to impose additional attribution and notice requirements compared to Apache-2.0, and some downstream projects prefer to avoid it when a permissively licensed alternative is available. Repository: https://github.com/apple-oss-distributions/mDNSResponder File: https://github.com/apple-oss-distributions/mDNSResponder/blob/main/mDNSCore/DNSDigest.c#L66 I’d like to clarify a few points: Is the MD5/digest code in DNSDigest.c still based on pre–OpenSSL-3.0 sources, such that retaining the legacy OpenSSL/SSLeay license block is intentional and required? If the goal were to simplify licensing (Apache-2.0 only), would Apple consider replacing this MD5 implementation with an Apache-2.0–licensed alternative (for example, code derived from OpenSSL 3.x or another permissive implementation)? Are there any technical or policy reasons (compatibility, crypto policy, platform APIs) that make such a replacement undesirable? Since GitHub issues and PRs are restricted for this repository, I’m asking here for guidance. If maintainers agree that such an update would be useful, I’d be happy to help by preparing a PR for review. I've also created a feedback report for this topic, the reference ID is FB21269078. Thanks for any clarification.

Hello team, Would this mean that content filters intended for all browsing can only be implemented for managed devices using MDM? My goal would be to create a content filtering app for all users, regardless of if their device is managed/supervised. thanks.

Hello, I am working to integrate the new com.apple.developer.networking.carrier-constrained.app-optimized entitlement in my iOS 26 app so that my app can use a carrier-provided satellite network, and want to confirm my understanding of how to detect and optimize for satellite network conditions. (Ref: https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.developer.networking.carrier-constrained.app-optimized ) My current approach: I plan to set the entitlement to true once my app is optimized for satellite networks. To detect if the device is connected to a satellite network, I intend to use the Network framework’s NWPath properties: isUltraConstrained — I understand this should be set to true when the device is connected to a satellite network. (Ref: https://developer.apple.com/documentation/network/nwpath/isultraconstrained ) linkQuality == .minimal — I believe this will also be set in satellite scenarios, though it may not be exclusive to satellite connections. (Ref: https://developer.apple.com/documentation/network/nwpath/linkquality-swift.enum/minimal ) Questions: Is it correct that isUltraConstrained will reliably indicate a satellite connection? Should I also check for linkQuality == .minimal, or is isUltraConstrained sufficient? Are there any additional APIs or best practices for detecting and optimizing for satellite connectivity that I should be aware of? Thank you for confirming whether my understanding and approach are correct, and for any additional guidance.

When setting new entitlements com.apple.developer.networking.carrier-constrained.appcategory and com.apple.developer.networking.carrier-constrained.app-optimized, I have a question about how URLSession should behave. I notice we have a way to specify whether a Network connection should allow ultra-constrained paths via NWParameters allowUltraConstrainedPaths: https://developer.apple.com/documentation/network/nwparameters/allowultraconstrainedpaths There does not appear to be a similar property on URLSessionConfiguration. In an ultra-constrained (eg. satellite) network, should we expect all requests made through an URLSession to fail? Does all network activity when ultra-constrained need to go through a NWConnection or NetworkConnection specifically configured with allowUltraConstrainedPaths, or can URLSession ever be configured to allow ultra-constrained paths?

I filed FB19631435 about this just now. Basically: starting with 15.6, we've had reports (internally and outternally) that after some period of time, networking fails so badly that it can't even acquire a DHCP lease, and the system needs to be rebooted to fix this. The systems in question all have at least 2 VPN applications installed; ours is a transparent proxy provider, and the affected system also had Crowdstrike's Falcon installed. A customer system reported seemingly identical failures on their systems; they don't have Crowdstrike, but they do have Cyberhaven's. Has anyone else seen somethng like this? Since it seems to involve three different networking extensions, I'm assuming it's due to an interaction between them, not a bug in any individual one. But what do I know? 😄

we use the api as NEHotspotConfigurationManager.shared.apply(hotspotConfig) to join a wifi, but we find that in in iphone 17+, some user report the time to join wifi is very slow the full code as let hotspotConfig = NEHotspotConfiguration(ssid: sSSID, passphrase: sPassword, isWEP: false) hotspotConfig.joinOnce = bJoinOnce if #available(iOS 13.0, *) { hotspotConfig.hidden = true } NEHotspotConfigurationManager.shared.apply(hotspotConfig) { [weak self] (error) in guard let self else { return } if let error = error { log.i("connectSSID Error while configuring WiFi: \(error.localizedDescription)") if error.localizedDescription.contains("already associated") { log.i("connectSSID Already connected to this WiFi.") result(["status": 0]) } else { result(["status": 0]) } } else { log.i("connectSSID Successfully connected to WiFi network \(sSSID)") result(["status": 1]) } } Normally it might only take 5-10 seconds, but on the iPhone 17+ it might take 20-30 seconds.

Hello eveybody,Currently I'm working on an app which connects to a device. During testing I encounter an internal error of NEHotspotConfigurationErrorDomain. See the log snippet:Domain=NEHotspotConfigurationErrorDomain Code=8 "internal error." UserInfo={NSLocalizedDescription=internal error.}This error appears randomly. In one day I encountered it three times. The only solution I can think of is catching this error somehow and then telling the user to restart the device.After this error appears, the wifi functionality of iOS in all third party apps seems to be broken. Only restarting helps as far as I know. Also there seems to be nothing we as app developers can do about it. Therefor I wonder if there is some way to prevent this error somehow? The only solution I can think of is catching this error somehow and then telling the user to restart the device.Also since there is not much information about this error on the web, it would be really nice if someone can clarify whats going on with this error.Regards.

Hi everyone, I’m exploring Network Extension options for a use case where I need to log and filter network activity at the packet level. More specifically, I need the ability to detect and potentially block certain TCP behaviors during the handshake. From everything I’ve tested, NEFilterPacketProvider seems to be the only Network Extension type that operates early enough in the flow. NEFilterDataProvider appears to receive flows after the TCP handshake is already completed. It also has some limitations with IP-based filtering (might include hostname instead of IP), inconsistent ICMP behavior, etc. So I went with NEFilterPacketProvider. However, I’m running into a major issue: extremely high CPU usage. To isolate the problem, I stripped my packet handler down to the simplest possible implementation — basically returning .allow for every inbound/outbound packet without any filtering logic. Even with that minimal setup, playing one or two videos in a browser causes the CPU usage of the extension to spike to 20–50%. This seems to be caused purely by the packet volume. I haven’t found any way to pre-filter packets before the handler is invoked, nor any documented method to significantly optimize packet handling at this stage. It’s possible I’m missing something fundamental. Questions: Has anyone else experienced this kind of high CPU usage with NEFilterPacketProvider? Is there any recommended way to reduce the packet handling overhead or avoid processing every single packet? Any known best practices or configuration tips? Thanks in advance!

We are observing a reproducible issue on some (not all) iPad models equipped with A16, where BLE streaming from multiple peripherals at ≥33–40 Hz results in uneven packet distribution, burst delivery, and application-level lag. The same application, peripherals, firmware, iOS version, and physical environment do not exhibit this behaviour on A14-based iPads (iPad 10). Affected Hardware: • iPad 11" with A16 • iOS versions: identical across tested devices • Issue affects some devices of the same model, not all Internal field data • ~25 affected • ~5 unaffected • Customers actively prefer iPad 10 (A14) due to stability When two or more BLE peripherals stream data concurrently at frequencies ≥33–40 Hz, affected iPads exhibit: • Uneven packet arrival timing • Burst delivery instead of uniform intervals • Increasing latency over time • Observable application-level lag This does not present as simple packet loss. Instead, packets arrive in clusters, breaking real-time assumptions. At ≤30–33 Hz, the issue does not reproduce. We tested: • One affected iPad 11 • One unaffected iPad 11 • Same iOS version • Same app build • Same peripherals • Same firmware • Same physical location • Same Wi-Fi state Only the affected device reproduces the issue. This rules out: • App logic • Peripheral firmware • iOS version • Environmental RF noise • Wi-Fi coexistence configuration Evidence Available We can provide: • Screenshots from a minimal test app showing packet counts • CSV files of packet timestamps • Source code for the BLE test app • Side-by-side comparison logs (affected vs unaffected device) All evidence is from the same app, built solely to measure packet timing. Additional Technical Notes • Issue persists after factory reset • Occurs without third-party BLE libraries (CoreBluetooth only) • Occurs regardless of foreground/background state • Not correlated with MTU size • Appears threshold-based (~33–40 Hz) • Appears device-specific, not model-wide