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 Wi-Fi (general): How to modernize your captive network developer news post Wi-Fi Fundamentals forums post Filing a Wi-Fi Bug Report forums post Working with a Wi-Fi Accessory forums post — This is part of the Extra-ordinary Networking series. Wi-Fi (iOS): TN3111 iOS Wi-Fi API overview technote Wi-Fi Aware framework documentation WirelessInsights framework documentation iOS Network Signal Strength forums post Network Extension Resources Wi-Fi on macOS: Forums tag: Core WLAN Core WLAN framework documentation 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 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.

This is a bit complicated to explain so bare with me. I am working on building an app that allows you to send real time video/camera captures from one Apple device to another. I am using a custom UDP protocol built on top of NWListener, NWBrowser, and NWConnection APIs. It works fine, but there are a few issues that seems to all be related to awdl: When transmitting via WiFi over the router (not using peer-to-peer), there are periodic interruptions when the wireless card on the device changes channels for awdl polling. This is resolved by changing the 5GHz WiFi channel on the router to channel 149 (or disabling AWDL altogether which is not really feasible). In order to work around number 1, I decided to build in an option to toggle/prefer peer-to-peer transmission in the app thinking that if everything goes over a peer-to-peer connection the jitter caused from the channel switching should go away. This also works, but with an important caveat. The default transmission is extremely choppy until you take an OS action that “elevates” the AWDL connection into “realtime” mode. I am using includePeerToPeer on the listener, browser, and connection as well as serviceClass interactiveVideo. For number 1, you can understand that asking users to change the channel on their router is not a great user experience, but the problem is the peer-to-peer connection workaround is also not great by default. For number 2, as an example of the behavior, I can send a stream from my Mac to my iPad over a peer-to-peer connection and it works but the video is very choppy until I move my cursor from my Mac to my iPad to trigger Universal Control. I captured the OS logs while doing this and can confirm that something happens to trigger “realtime” mode on the AWDL connection. After that, the streaming is totally smooth with zero latency. Some log samples: 2026-03-19 12:42:01.277968-0400 0x1ae294c Default 0x0 495 3 rapportd: (CoreUtils) [com.apple.rapport:CLinkD] Update client from UniversalControl:697 2026-03-19 12:42:01.278031-0400 0x1ae294c Default 0x0 495 0 rapportd: (CoreUtils) [com.apple.CoreUtils:AsyncCnx] CLinkCnx-6089: Connect start: 'CLink-ed3b9618b4e0._companion-link._tcp.local.%13' 2026-03-19 12:42:01.278149-0400 0x1ae294c Default 0x0 495 0 rapportd: (CoreUtils) [com.apple.CoreUtils:AsyncCnx] CLinkCnx-6089: Querying SRV CLink-ed3b9618b4e0._companion-link._tcp.local.%13 2026-03-19 12:42:01.279454-0400 0x1ae253a Info 0x0 382 0 wifip2pd: [com.apple.awdl:datapathInitiator] Created AWDLDatapathInitiator clink-ed3b9618b4e0._companion-link._tcp.local <To: 2e:f2:5a:15:76:52> 2026-03-19 12:42:01.279498-0400 0x1ae294c Default 0x0 495 0 rapportd: (CoreUtils) [com.apple.CoreUtils:AsyncCnx] CLinkCnx-6089: Resolving DNS f970afcc-1f1c-47af-a3f3-0236c9f9bbb0.local.%13 2026-03-19 12:42:01.279588-0400 0x1ae253a Default 0x0 382 0 wifip2pd: [com.apple.awdl:datapathInitiator] AWDLDatapathInitiator clink-ed3b9618b4e0._companion-link._tcp.local <To: 2e:f2:5a:15:76:52> was started 2026-03-19 12:42:01.282537-0400 0x1ae294c Default 0x0 495 0 rapportd: (Network) [com.apple.network:path] nw_path_evaluator_start [5C54D967-624D-4269-B080-6C7AE63218C7 IPv6#1e905043%awdl0.49154 generic, attribution: developer] path: satisfied (Path is satisfied), interface: awdl0[802.11], dns, uses wifi 2026-03-19 12:42:01.596450-0400 0x1ae253a Debug 0x0 382 0 wifip2pd: [com.apple.awdl:driver] Received event realtimeMode 2026-03-19 12:42:01.596589-0400 0x1ae253a Default 0x0 382 0 wifip2pd: [com.apple.awdl:interface] Realtime mode updated true I noticed that on iOS 26 and iPadOS 26 a realtime mode was added specifically to the Wi-Fi Aware API which I assume does what I want: https://developer.apple.com/documentation/wifiaware/waperformancemode/realtime, but I am looking for a solution that works with the existing network API and also on previous OS versions. I have already tried a lot of things, but is there any way to programmatically trigger “realtime” mode? For additional context, the goal here is to have extremely low latency that also works for gaming. The actual latency introduced in 1 is approximately 30-50ms around once a second… adding a buffer to the stream makes the video completely smooth, but the extra delay on the receiver end is not acceptable for this use case. Any help or ideas would be appreciated. I can’t easily share a reproduce case right now, and even if I could, getting multiple devices into the exact state along with the router configuration in order to reproduce is going to be pretty difficult anyway.

I am investigating a connectivity issue reported by a user running latest iOS 26.4 Public Beta on an iPhone 17 Pro Max. Unfortunately, I am unable to reproduce this behavior on my end as I do not have access to an iPhone 17 Pro Max for testing, and my current devices do not exhibit the issue. However, the user's logs suggest a system-level networking issue : Symptoms: Flutter App (package dio): Requests fail with The connection errored: Failed host lookup: 'mydomain.com' Firebase SDK: Unable to fetch Firestore documents Duration: The outage is random, lasting between 5 to 15 minutes before self-resolving Scope: It affects both Wi-Fi and Cellular data By the way I found this report from another developer experiencing the exact same behavior: "I run a mobile app that has millions of users. As of 1-2 weeks ago, we started getting reports that the app isn't working (failing to connect). It then goes back to connecting anywhere between 5 to 15-20 mins later. Every single one of those users was running iOS 26.4 beta, and their phones ranged from iPhone 17 PRO Max to regular iPhone 17s, to iPhone 16 PROs and Maxs. The only other thing is that all these users also had Apple Private Relay enabled. During the time the app wasn't able to connect, other apps on their phones like YouTube, also failed to connect. The issue is persistent whether on Wifi or cellular, didn't matter. I upgraded my iPhone 16 PRO Max to iOS 26.4, and wasn't experiencing the issue. I enabled Private Relay - and a few mins later on my own phone, I couldnt connect on my own app, and YouTube/Gmail also were experincing issue. It self-resolved 5-10 mins later. But it kept happening throughout the day. I've tested Network reset, I've also re-installed the apps, both still continued to have those weird intermittent outages. I just updated the phone to the latest version that was released a day ago, so far I'm not experiencing it, but as you can imagine, this is such a weird behaviour that it's concerning for me that I can't figure out the exact way to replicate it." I asked the user to test with iCloud Private Relay disabled, and it immediately fixed the problem -> so maybe this suggests that it might be related to how Private Relay handles traffic or DNS resolution in this beta ? Are other developers seeing an increase in SocketException or host lookup failures on the 26.4 Beta? Is this a known regression related to Private Relay that is expected to be patched before the RC/Final release?

Hello, I have implemented a URL Filter using the sample provided here: Filtering Traffic by URL. I am also using an App Group to dynamically manage the Bloom filter and block list data. However, when I update my block list URLs and create a new Bloom filter plist in the App Group, the extension does not seem to use the updated Bloom filter even after the prefetch interval expires. Also for testing purpose can I keep this interval to 10 mins or below ?

Error 8 in the NEHotspotConfigurationError domain is .internal, aka NEHotspotConfigurationErrorInternal. This error typically indicates that something went wrong in some sort of expected way, but we decided not to surface the exact cause [1]. This has come up a bunch of times before on the forums, and I have various titbits to share. To start, I want to address some specific cases: You’ll see this error if your app isn’t signed with the com.apple.developer.networking.HotspotConfiguration entitlement. To fix this, use Xcode’s Signing & Capabilities editor to add the Hotspot capability to your app. Historically developers reported a situation where once they encountered the error it would show up consistently, but then it would go away on restarting the device. If you see behaviour like that, that’s definitely a bug and I encourage you to file it as such. I have more about filing such bugs in Filing a Wi-Fi Bug Report. Of course, you have to wait to reproduce the error again before you’ll be able to file that bug, because the act of restarting cleared the issue. I’ve seen reports where such problems only occur on a specific type of device, for example, on iPhone 16 but not on earlier or later iPhones. That’s definitely something that Apple should investigate, and I recommend that you file a bug about it. If the problem is being reported by your users but you can’t reproduce it yourself, consider the various suggestions in Using a Sysdiagnose Log to Debug a Hard-to-Reproduce Problem. Assuming you’re still here (-: the next step is to determine whether the problem is specific to NEHotspotConfigurationManager or not. Try joining the accessory’s network from Settings > Wi-Fi. Does that also have problems? If so, that’s not something we can help you with here on the forums. The focus of the Apple Developer Forums is primarily to help developers with the APIs in Apple’s various platform SDKs [2]. We’re not set up to help accessory developers with Wi-Fi issues. However, there are still things you can do, as I explain in Filing a Wi-Fi Bug Report. At this point you have an error that: Persists across restarts Happens with all Apple devices You can reproduce Only affects NEHotspotConfigurationManager If that’s correct then there are a couple of things you might look at: Coerce the error to an NSError and print that. Does it reveal anything interesting? Also check the underlying error property (NSUnderlyingErrorKey) for hints. When reproducing the error, monitor the system log for log entries in the com.apple.networkextension subsystem. Do those offer any clues? Note For lots of hints and tips about the system log, see Your Friend the System Log. And finally, if you have questions about this case, feel free to start a thread here on the forums and we’ll try to help you out. Put it in the App & System Services > Networking subtopic and tag it with Network Extension. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" [1] There’s also the .unknown error. See this post for a brief summary of the difference. [2] And with Apple tools and some developer-oriented services. Revision History 2026-03-18 Added a missing entitlement bullet to the specific case list. 2026-03-17 First posted.

Every now and again I end up helping a developer with a Wi-Fi issue. These fall into two groups: User-level Wi-Fi issues Development Wi-Fi issues A user-level Wi-Fi issue is one where the developer hasn’t created any of the products involved. An example of this is when you’re developing an app for an accessory and iOS is having problems connecting to that accessory but you don’t control the accessory’s firmware. In general, I recommend that you escalate such issues to the accessory vendor. They can then run their own investigation and, if necessary, file their own bug report. A development Wi-Fi issue is one that directly affects one of your products. For example, you’re developing a Wi-Fi accessory and iOS is having problems connecting to it. In that case, the onus is on you [1] to investigate why things are failing. If your conclusion is that iOS is behaving incorrectly, file a bug about that. IMPORTANT If you do file a bug in the context of some forums thread, please post your bug number to the thread, just for the record. When filing this sort of bug report it’s important to provide: Solid evidence that the problem is on the Apple side of the fence Enough information for Apple’s engineers to investigate it effectively Let’s start with that second point. If you can reproduce the problem reliably, install the Wi-Fi debug profile on your device, reproduce the problem, noting down a rough timestamp, and include the resulting logs and that timestamp in your bug report. Also, consider attaching a packet trace. There are three options here: Record a packet trace from the perspective of the Apple device. On iOS, use an RVI packet trace for this. Record a packet trace from the perspective of your accessory. Record a Wi-Fi level packet trace. You can do this from your Mac (see Recording a Wi-Fi Packet Trace) but it might be easier to do this with the infrastructure you used during the bring up of your accessory. It’s fine to include all three (-: Also include any relevant context about the issue. For example: If the issue is tied to a specific device model (In that case, it’d be good to include the above information for both the successful and failing cases.) If the problem shows up when joining from Settings > Wi-Fi, or whether it’s tied to a specific API, like NEHotspotConfigurationManager Finally, make sure to include an explanation of why you think this is an Apple bug, referencing specific items in the logs and packet traces that you attached. Of course, it’s only possible to do all of this if you can reproduce the problem. Investigating an intermittent issue based on reports coming in from users is much harder. It’s OK to file a bug about such issues, but your bug might not be actionable. At a minimum you should aim to include a sysdiagnose log with your bug. IMPORTANT This log has to be taken shortly after reproducing the problem. Don’t just attach any old log. One option is to request such a log from your users. I talk more about this in Using a Sysdiagnose Log to Debug a Hard-to-Reproduce Problem. You can also ask your users to file their own bugs using the Feedback Assistant app. It should automatically capture and attach a sysdiagnose log. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" [1] Well, your organisation. It’s rare to find a team where the same engineer works on both the iOS app and the accessory firmware. But if that’s you, good job!

Hi Team, I want to retrieve the list of nearby Wi-Fi networks (SSIDs) directly inside the app. Currently, I can see the available Wi-Fi networks by going to Settings → Wi-Fi on the device, but I would like to access that scan list programmatically within my application. I am developing the app using the Angular Ionic platform. On Android, I am able to get the nearby Wi-Fi scan list using the npm package @capgo/capacitor-wifi (v8.1.8). However, on iOS, the scan results are not being returned. If anyone has experience with this or knows how to achieve Wi-Fi scanning on iOS in Ionic/Capacitor, please let me know. Thanks.

Hi Team, I want to retrieve the list of nearby Wi-Fi networks (SSIDs) directly inside the app. Currently, I can see the available Wi-Fi networks by going to Settings → Wi-Fi on the device, but I would like to access that scan list programmatically within my application. I am developing the app using the Angular Ionic platform. On Android, I am able to get the nearby Wi-Fi scan list using the npm package @capgo/capacitor-wifi (v8.1.8). However, on iOS, the scan results are not being returned. If anyone has experience with this or knows how to achieve Wi-Fi scanning on iOS in Ionic/Capacitor, please let me know. Thanks.

Hi, I'v got the error by using NEHotspotConfiguration to connect a wifi spot but get:NEHotspotConfigurationErrorDomain code=8. I hope to get the same result as when scanning the code with the system camera. A pop-up window will appear, and I just need to click "Join" to successfully connect. Here's the logs: [OneAppWifi][iOS] handleCheckWifiEnabled start (iOS 12+) [OneAppWifi][iOS] handleCheckWifiEnabled pathUpdateHandler status=satisfied [OneAppWifi][iOS] handleConnectWifi start, ssid=OPPO Find X6 Pro, pwd=len=16, authType=Optional("sae"), hidden=false [OneAppWifi][iOS] handleConnectWifi cancelPendingConnection before new request ssid=OPPO Find X6 Pro [OneAppWifi][iOS] cancelPendingConnection called, errorCode=nil, currentSsid=nil [OneAppWifi][iOS] cancelPendingConnection silent cancel, just clear pendingConnectResult [OneAppWifi][iOS] handleConnectWifi apply completion with error, domain=NEHotspotConfigurationErrorDomain, code=8, userInfo=["NSLocalizedDescription": internal error.] [OneAppWifi][iOS] resolveNEError NEHotspotConfigurationErrorDomain code=8 [OneAppWifi][iOS] resolveNEError systemConfiguration / internal, map to connection_failed [OneAppWifi][iOS] handleConnectWifi resolved as failure errorCode=Optional("connection_failed") for ssid=OPPO Find X6 Pro [OneAppWifi][iOS] firePendingResult value=["success": false, "errorCode": Optional("connection_failed")], currentSsid=Optional("OPPO Find X6 Pro")

Hello, I submitted a Network Extension entitlement request (Packet Tunnel Provider) and opened case 102837721995. The case history says Apple sent a message on March 12, but I did not receive it and cannot reply through the support portal. Could someone from Apple Developer Support check the case? Also, it is possible that I misunderstood something or submitted the wrong entitlement request. My application will use WireGuard to establish the VPN connection. If a different entitlement is required for this scenario, please let me know. Thank you.

When using the official Wi-Fi Aware demo app on iOS, with the iOS device configured as a NAN Subscriber, after successfully establishing a peer-to-peer connection with another device via Wi-Fi Aware (NAN), the network path object nwPath.availableInterfaces does not list the nan0 virtual network interface. The nan0 interface is the dedicated NAN (Neighbor Aware Networking) interface used for Wi-Fi Aware data communication. Its absence from availableInterfaces prevents the app from correctly identifying/using the NAN data path, breaking expected Wi-Fi Aware data transmission logic. log: iOS works as subscriber: [onPathUpdate] newPath.availableInterfaces: ["en0"] iOS works as publisher: [onPathUpdate] newPath.availableInterfaces: ["nan0"]

com.apple.main-thread 0 StarMaker 0x5c40854 _isPlatformVersionAtLeast.cold.2 + 4425680980 1 StarMaker 0x526d278 -[FPRScreenTraceTracker displayLinkStep] + 191 (FPRScreenTraceTracker.m:191) 2 QuartzCore 0xbe924 CA::Display::DisplayLinkItem::dispatch(CA::SignPost::Interval<(CA::SignPost::CAEventCode)835322056>&) + 64 3 QuartzCore 0x9bf38 CA::Display::DisplayLink::dispatch_items(unsigned long long, unsigned long long, unsigned long long) + 880 4 QuartzCore 0xaf770 CA::Display::DisplayLink::dispatch_deferred_display_links(unsigned int) + 360 5 UIKitCore 0x7dee4 _UIUpdateSequenceRunNext + 128 6 UIKitCore 0x7d374 schedulerStepScheduledMainSectionContinue + 60 7 UpdateCycle 0x1560 UC::DriverCore::continueProcessing() + 84 8 CoreFoundation 0x164cc __CFMachPortPerform + 168 9 CoreFoundation 0x460b0 CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION + 60 10 CoreFoundation 0x45fd8 __CFRunLoopDoSource1 + 508 11 CoreFoundation 0x1dc1c __CFRunLoopRun + 2168 12 CoreFoundation 0x1ca6c _CFRunLoopRunSpecificWithOptions + 532 13 GraphicsServices 0x1498 GSEventRunModal + 120 14 UIKitCore 0x9ddf8 -[UIApplication _run] + 792 15 UIKitCore 0x46e54 UIApplicationMain + 336 16 StarMaker 0x50c965c main + 18 (main.m:18) 17 ??? 0x19a9dae28 (缺少) Thread 0 libsystem_kernel.dylib 0x67f4 __semwait_signal + 8 1 libsystem_c.dylib 0xc7e4 nanosleep + 220 2 ZorroRtcEngineKit 0x1eb0f8 std::__Cr::this_thread::sleep_for(std::__Cr::chrono::duration<long long, std::__Cr::ratio<1l, 1000000000l>> const&) + 198 (pthread.h:198) 3 ZorroRtcEngineKit 0x27d30 zorro::KbLog::Loop() + 88 (kblog.cc:88) 4 ZorroRtcEngineKit 0x286e8 <deduplicated_symbol> + 4667967208 5 libsystem_pthread.dylib 0x444c _pthread_start + 136 6 libsystem_pthread.dylib 0x8cc thread_start + 8 Thread 0 libsystem_kernel.dylib 0x67f4 __semwait_signal + 8 1 libsystem_c.dylib 0xc7e4 nanosleep + 220 2 ZorroRtcEngineKit 0x1eb0f8 std::__Cr::this_thread::sleep_for(std::__Cr::chrono::duration<long long, std::__Cr::ratio<1l, 1000000000l>> const&) + 198 (pthread.h:198) 3 ZorroRtcEngineKit 0x19a4e4 zorro::ZkbLog::Loop() + 157 (zlog.cc:157) 4 ZorroRtcEngineKit 0x286e8 <deduplicated_symbol> + 4667967208 5 libsystem_pthread.dylib 0x444c _pthread_start + 136 6 libsystem_pthread.dylib 0x8cc thread_start + 8 Thread 0 libsystem_kernel.dylib 0x67f4 __semwait_signal + 8 1 libsystem_c.dylib 0xc7e4 nanosleep + 220 2 ZorroRtcEngineKit 0x1eb0f8 std::__Cr::this_thread::sleep_for(std::__Cr::chrono::duration<long long, std::__Cr::ratio<1l, 1000000000l>> const&) + 198 (pthread.h:198) 3 ZorroRtcEngineKit 0x19c4d8 zorro::QosManager::Loop() + 966 (string:966) 4 ZorroRtcEngineKit 0x286e8 <deduplicated_symbol> + 4667967208 5 libsystem_pthread.dylib 0x444c _pthread_start + 136 6 libsystem_pthread.dylib 0x8cc thread_start + 8

We are assisting a client with their app integration. The client believes that NEPacketTunnelProvider, NEHotspotHelper, and NEHotspotManager extensions stop functioning if the containing app hasn't been launched by the user within some recent window (e.g. 30, 60, or 90 days). We haven't been able to find any documentation supporting this claim. Specifically, we'd like to know: Is there any app launch recency requirement that would cause iOS to stop invoking a registered NEHotspotHelper or NEHotspotManager configuration? Is there any app launch recency requirement that would cause iOS to tear down or prevent activation of a NEPacketTunnelProvider? More generally, does iOS enforce any kind of "staleness" check on apps that provide Network Extension or Hotspot-related functionality, where not being foregrounded for some period causes the system to stop honoring their registrations? If such a mechanism exists, we'd appreciate any pointers to documentation or technical notes describing the behavior and timeframes involved. If it doesn't exist, confirmation would help us guide our client's debugging in the right direction. Thank you.

I am referencing: https://developer.apple.com/documentation/foundation/pausing-and-resuming-uploads Specifically: You can’t resume all uploads. The server must support the latest resumable upload protocol draft from the HTTP Working Group at the IETF. Also, uploads that use a background configuration handle resumption automatically, so manual resuming is only needed for non-background uploads. I have control over both the app and the server, and can't seem to get it to work automatically with a background url session. In other words, making multiple requests to get the offset then upload, easy but I am trying to leverage this background configuration resume OS magic. So anyone know what spec version does the server/client need to implement? The docs reference version 3, however the standard is now at like 11. Of course, I am trying out 3. Does anyone know how exactly this resume is implemented in iOS, and what exactly it takes care of? I assumed that I can just POST to a generic end point, say /files, then the OS receives a 104 Location, and saves that. If the upload is interrupted, when the OS resumes the upload, it has enough information to figure out how to resume from the exact offset, either by making a HEAD request to get the offset, or handle a 409. I am assuming it does this, as if it doesn't, the 'uploads that use a background configuration handle resumption automatically' is useless, if it just restarts from 0. Note, of course making individual POST/HEAD/PATCH requests manually works, but at that point I'm not really leveraging any OS auto-magic, and am just consuming an API that could really implement any spec. This won't work in the background, as the OS seems to disallow random HTTP requests when it wakes the app for URLSession background resumes. As of right now, I have it 'partially' working, insofar as the app does receive the 104 didReceiveInformationalResponse url delegate call, however it seems to then hang; it stops sending bytes, seemingly when the 104 is received. However, the request does not complete. In other words, it doesn't seem to receive a client timeout or otherwise indicate the request has finished. Right now, I am starting a single request, POSTing to a /files end point, i.e. I am not getting the location first, then PATCHing to that, as if I do that, the OS 'automatic' resuming fails with a 409, i.e. it doesn't seem to make a HEAD request and/or use the 409 offset correction then continue with the PATCH. Any idea what could be going on?

Hello and Good day! We are conducting Bonjour Conformance Test (BCT) for Printer device. BCT result is PASSED but with warning in Multicast DNS, specifically, WARNING: SHARED REPLY TIMING - UNIFORM RANDOM REPLY TIME DISTRIBUTION Other Shared Reply Timing is passed: PASSED: MULTIPLE QUESTIONS - SHARED REPLY TIMING - UNIFORM RANDOM REPLY TIME DISTRIBUTION Environment: BCT Tool Version: 1.5.4 (15400) MacOS Sequioa 15.5 DUT Firmware : Linux Debian 9 Apple mDNSResponder 1790.80.10 Service types: _ipps._tcp, _uscans._tcp, _ipp._tcp, _uscan._tcp Router : NEC AtermWR8370N Setup: 1-to-1 [Mac->Router<-DUT connection] Based on debug.log, this is where WARNING occurs: NOTICE 2026-03-04 10:51:06.870187+0900 _shared_reply_timing 04103: Shared reply response times: min = 26ms, max = 114ms, avg = 65.50ms WARNING 2026-03-04 10:51:06.870361+0900 _shared_reply_timing 04136: 50 percent of the replies within the correct range fell in the interval 20ms and 46ms (should be close to 25%). PASSED (SHARED REPLY TIMING) In the same debug.log for MULTIPLE QUESTIONS - SHARED REPLY TIMING is PASSED: NOTICE 2026-03-04 10:52:29.912334+0900 _shared_reply_timing 04103: Shared reply response times: min = 22ms, max = 112ms, avg = 78.00ms DEBUG_2 2026-03-04 10:52:29.912849+0900 recv_packet 01997: received packet (558 bytes) PASSED (MULTIPLE QUESTIONS - SHARED REPLY TIMING) [Details] Looking at Bonjour_Conformance_Guideline.pdf https://download.developer.apple.com/Documentation/Bonjour_Conformance_Test_Guideline/Bonjour_Conformance_Guideline.pdf there were some differences: In 1.6.2 Expected Result: Test Result File of Test that All Tests Passed, this is not displayed: PASSED: SHARED REPLY TIMING - UNIFORM RANDOM REPLY TIME DISTRIBUTION And in II.8 Shared Reply Timing: (Ideally, 25% of the answers should fall in each 21ms quadrant of the range 20ms - 125ms.) and comparing to the debug.log, there was a discrepancy of the interval, because 20ms and 46ms is 26ms interval. From RFC6762 6. Responding, Ideal range is from 20ms-120ms Because of this, please advise on the questions below: I would like to know on the possible cause and resolution for these WARNINGS. And since in current BCT result, (Test result integrity signature is generated), I would like to know if this is acceptable for BCT certification. Thank you.

We have a macOS system extension with NETransparentProxyProvider which is able to intercept traffic and handle it. We also wanted to setup few search domains from our network extension. However, unlike PacketTunnelProvider, NEDNSSettings are completely ignored with NETransparentProxyProvider. So whats the best way to setup few DNS search domains when using NETransparentProxyProvider.

Hey! We discovered an unexpected side-effect of enabling enforceRoutes in our iOS VPN application - video airplay from iOS to tvOS stopped working (Unable to Connect popup appears instead). Our flags combination is: includeAllNetworks = false enforceRoutes = true excludeLocalNetworks = true Interestingly, music content can be AirPlayed with the same conditions. Also, video AirPlay from iOS device to the macOS works flawlessly. Do you know if this is a known issue? Do you have any advice if we can fix this problem on our side, while keeping enforcRoutes flag enabled?

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?

We’re having an iPad issue accessing the local network with iPadOS 26.3. We have an automation system that tests our app on an iPad using accessibility tags. the XCTest test code sends messages from the iPad via TCP/IP to setup external test equipment. The messages abruptly stopped transmitting across the iPad blood-brain barrier with iPadOS 26.3 (26.2.1 and earlier works fine). The technique that worked involved installing a helper app with the same bundleID as our app, allowing the helper app to access the network, and when our app runs it has network access through the helper. It’s clever and kludgey. Forums that we referenced in the past: https://developer.apple.com/forums/thread/663858 TN3179: Understanding local network privacy | Apple Developer Documentation I suspect that something was changed in 26.3 that closed our window. I need two things: ID what is different in 26.3 and fix the automation system. If there’s a new way for XCUITest code to access the local network I’m happy to try it out.

I want to track down which part of an app contacts a given domain listed in its App Privacy Report. Following the instructions given here I am able to capture a packet trace, but traffic to the domain in question is encrypted using QUIC. Is there a way to insert e.g. mitmproxy into the capture process in order to get hold of the SSLKEYLOGFILE so that I can decrypt the traffic?

I'm using NEPacketTunnelProvider to intercept DNS queries, forward them upstream, and inject the responses back via writePacketObjects(). This works correctly for responses under ~500 bytes. For larger responses (~893 bytes, e.g. DNS CERT records), writePacketObjects() returns without error but mDNSResponder never receives the packet — it retries 3–4 times and then times out. What I have verified: IP and UDP checksums are correct UDP length and IP total length fields are correct Maximum packet size (MTU) set to 1500 in NEIPv4Settings/NEIPv6Settings Approaches tried: Injecting the full 921-byte packet — writePacketObjects() succeeds but the packet never reaches mDNSResponder IP-level fragmentation — fragments appear to be silently dropped Setting the TC (truncation) bit — mDNSResponder does not retry over TCP Truncating the response to ≤512 bytes — the packet arrives but the data is incomplete Questions: Is there a supported way to deliver a DNS response larger than 512 bytes through NEPacketTunnelFlow? Does NEPacketTunnelProvider impose an undocumented packet size limit below the configured MTU? Does mDNSResponder silently discard responses larger than 512 bytes when the original query had no EDNS0 OPT record? Is there a way to signal that larger responses are supported? Are IP-level fragments reliably delivered through writePacketObjects()? Tested on iOS 26.3, physical device.