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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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DHCP broken when device wakeup
Many times the device totally lost connectivity, WIFI is completely down, no ip was assigned after device wakeup. From system log I can see BPF socket for DHCP was closed and detached right after attached to en0 in DHCP INIT phase, as result even the DHCP server sent back OFFER(I see server sent OFFER back from packet capture), but there is no persistent BPF socket since it is closed reception during the entire INIT phase. It is definitely an OS issue, is it a known issue? Please help understand Why BPF socket was close right after sending DISCOVER? Default 0x0 0 0 kernel: bpf26 attached to en0 by configd:331 2026-03-25 14:06:33.625851+0100 0x31dea Default 0x0 0 0 kernel: bpf26 closed and detached from en0 fcount 0 dcount 0 by configd:331 System log and packet capture attach, please check.
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6d
NWConnectionGroup with Both Datagram and Non-datagram streams
I want to know the right way/API/usage to use NWConnectionGroup to send both datagram and non-datagram stream. I am currently working on an P2P video streaming app. I want to leverage NWConnectionGroup over QUIC to handle both message channel (traditionally handled by a TCP connection) and media channel (traditionally handled by sth. over UDP) to transmit SRT packets back and forth. I created a NWConnectionGroup and it worked fine on non-datagram parts. The problems are with datagram part. I tried extracting a connection with datagram = true either from the group or from message, doesn't and in some cases it breaks other non-datagram connections. I currently send datagram directly using the NWConnectionGroup.send(content:completion). It kinda works but I keep seeing it canceled a lot of messages, which breaks SRT shortly after start. The warnings belong flooded my console. (Seems like want me to create a connection to transmit datagram, how?) nw_connection_create_with_connection [C1600] Original connection not yet connected nw_connection_group_create_connection_for_endpoint_and_parameters [G1] failed to create connection with parameters quic, local: fe80::439:68b4:6ec2:694%en0.60517, definite, attribution: developer, server I must use it in wrong way. What should I do to fix it?
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132
Jan ’26
Why nslookup dns queries not routed to NETransparentProxyProvider
I’m using an NETransparentProxyProvider where I add UDP-53 rules to intercept DNS queries from a private application. These queries are resolved locally on the endpoint by returning a custom DNS response. Example Rules look like this: NENetworkRule(destinationHost: NWHostEndpoint(hostname: "mypaapp.com", port: 53),protocol:.UDP) This works as expected through browser and ping. handleNewUDPFlow/handleNewFlow with NEAppProxyUDPFlow gets called where custom dns response get written. Using nslookup mypaapp.com doesn't works. Why does this behaves differently for nslookup?
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122
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
System Information in macOS 26.2 RC no longer shows Wi-Fi SSIDs
System Information in macOS from 26.0 to 26.2 RC no longer provides Wi-Fi SSIDs; instead, it displays "< redacted> " for every SSID on my two MacBooks. This issue has been fixed in macOS 26.1 beta and macOS 26.2 beta, but it returns in the RC and the Final Release versions. Is it an expected behaviour or a bug in the Release Candidate? MacBook Air 2025: MacBook Pro 2021:
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Dec ’25
An error occurred when downloading a background assets packs hosted by Apple.
On macOS Tahoe26.0, iOS 26.0 (23A5287g), Xcode 26.0 beta 3 (17A5276g) 1、Follow this tutorial Downloading asset packs hosted by Apple When i download a background asset packs hosted by Apple, Xcode callback "Download failed: The helper received an invalid server response with the status code “400”." Before downloading, I uploaded the three aar files to the Apple server using the Transporter app. Three Manifest.json content is: {"assetPackID":"bdassets2","downloadPolicy":{"onDemand":{}},"fileSelectors":[{"file":"1.jpg"},{"file":"2.pag"},{"file":"3.mp4"}],"platforms":["iOS"]} and {"assetPackID":"bdassets1","downloadPolicy":{"prefetch":{"installationEventTypes":["firstInstallation","subsequentUpdate"]}},"fileSelectors":[{"file":"1.jpg"},{"file":"2.pag"},{"file":"3.mp4"},{"directory":"a1"}],"platforms":["iOS"]} and {"assetPackID":"bdassets0","downloadPolicy":{"essential":{"installationEventTypes":["firstInstallation","subsequentUpdate"]}},"fileSelectors":[{"file":"1.jpg"},{"file":"2.pag"},{"file":"3.mp4"},{"directory":"a1"}],"platforms":["iOS"]} The same error was reported when the three aar files were obtained. I obtained it using the following code: do {       let assetPack = try await AssetPackManager.shared.assetPack(withID: "bdassets2")       try await AssetPackManager.shared.ensureLocalAvailability(of: assetPack)     } catch {       print("Download failed:", error)     } 2、Follow this tutorial Testing your asset packs locally I use this command line to start the test server:xcrun ba-serve --host 172.17.9.62 bdassets2.aar, The content displayed on the terminal is: Loading asset packs… Loading the asset pack at “bdassets2.aar”… Choose an identity in the panel to continue. Listening on port 56061… When running the project, Xcode reports an error:Download failed: Could not connect to the server. I use iPhone directly visit this website: https://172.17.9.62:56061, on the page display "Hello, world!" There are too few error messages in both of the above questions. I have no idea what the specific reasons are.I hope someone can offer some guidance. Best Regards.
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Jul ’25
joinAccessoryHotspot does not fail if wrong passphrase is provided
I am trying to connect to an accessory's WiFi network using the below code and I always see the message "connection succeded" even if I provide an incorrect passphrase. I tried with different accessories and see the same behavior. hotspotConfigurationManager.joinAccessoryHotspot(accessory, passphrase: passphrase) { error in if let error = error { print("connection failed: \(error.localizedDescription)") } else { print("connection succeeded") } }
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167
Apr ’25
Disable Local Network Access permission check
I'm using a Mac Studio in a homelab context and use Homebrew to manage the installed services. The services include things that access the local network, for example Prometheus which monitors some other servers, a reverse proxy which fronts other web services on the network, and a DNS server which can use another as upstream. Local Network Access permissions make it impossible to reliably perform unattended updates of services because an updated binary requires a GUI login to grant local network permissions (again). I use brew services to manage the services as launchd agents, i.e. they run in a non-root GUI context. I know that I can also use sudo brew services which instead installs the services as launchd daemons, but running services as root has negative security implication and generally doesn't look like a good idea to me. If only there was a way to disable local network access checks altogether…
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425
Feb ’26
Replacing Packet Filter (pf) with Content Filter for VPN Firewall Use Case
Hi, We're in the process of following Apple’s guidance on transitioning away from Packet Filter (pf) and migrating to a Network Extension-based solution that functions as a firewall. During this transition, we've encountered several limitations with the current Content Filter API and wanted to share our findings. Our VPN client relies on firewall functionality to enforce strict adherence to split tunneling rules defined via the routing table. This ensures that no traffic leaks outside the VPN tunnel, which is critical for our users for a variety of reasons. To enforce this, our product currently uses interface-scoped rules to block all non-VPN traffic outside the tunnel. Replicating this behavior with the Content Filter API (NEFilterDataProvider) appears to be infeasible today. The key limitation we've encountered is that the current Content Filter API does not expose information about the network interface associated with a flow. As a workaround, we considered using the flow’s local endpoint IP to infer the interface, but this data is not available until after returning a verdict to peek into the flow’s data—at which point the connection has already been established. This can result in connection metadata leaking outside the tunnel, which may contain sensitive information depending on the connection. What is the recommended approach for this use case? NEFilterPacketProvider? This may work, but it has a negative impact on network performance. Using a Packet Tunnel Provider and purely relying on enforceRoutes? Would this indeed ensure that no traffic can leak by targeting a specific interface or by using a second VPN extension? And more broadly—especially if no such approach is currently feasible with the existing APIs—we're interpreting TN3165 as a signal that pf should be considered deprecated and may not be available in the next major macOS release. Is that a reasonable interpretation?
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275
May ’25
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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381
Feb ’26
Wi-Fi connectivity Issue - Captive.apple.com returns “application/octet-stream” instead of “text/html”,
In our system, when a user enables a mobile hotspot and the system connects to it, the system attempts to verify WIFI availability by sending an HTTP GET request to http://captive.apple.com. Normally, the server returns: HTTP Status: 200 (OK) Content-Type: text/html This has always been used as a sign of normal connectivity. Issue: Since last Friday, the server sometimes responds with: Content-Type: application/octet-stream When this occurs, our system determines that the network is unavailable and displays a connection warning (a “!” icon). Question: Has Apple recently made any backend or CDN configuration changes to captive.apple.com that could affect the response type? Any advice how can we solve this problem? Thanks!
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1k
Jan ’26
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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NEURLFilter production build fails with _NSURLErrorPrivacyProxyFailureKey — how to provision OHTTP privacy proxy for bundle?
Summary I'm implementing NEURLFilter with the com.apple.developer.networking.networkextension.url-filter-provider entitlement for a system-wide URL filtering feature. The feature works perfectly in development-signed builds (connecting successfully to my PIR server over extended testing) but every production-signed build fails before any network call is made. NEURLFilterManager reports .serverSetupIncomplete (code 9). After installing the NetworkExtension debug profile, the unredacted com.apple.CipherML logs reveal the cause: no privacy proxy is provisioned for this bundle identifier, and the connection is configured proxy fail closed. Environment iOS 26 Entitlement: com.apple.developer.networking.networkextension.url-filter-provider Extension point: com.apple.networkextension.url-filter-control PIR server configured via NEURLFilterManager.setConfiguration(...) Privacy Pass issuer configured Dev-signed builds: working correctly, connecting to the PIR server Production-signed builds (both TestFlight and distribution): failing identically The Error Chain Surfaced to the app via NEURLFilterManager.lastDisconnectError: NEURLFilterManager.Error.serverSetupIncomplete (code 9) ← NEAgentURLFilterErrorDomain Code 3 ← com.apple.CipherML Code 1100 "Unable to query status" ← com.apple.CipherML Code 1800 (error details were logged and redacted) After installing the VPN (NetworkExtension) debug profile, the unredacted com.apple.CipherML subsystem shows: queryStatus(for:options:) threw an error: Error Domain=NSURLErrorDomain Code=-1009 "The Internet connection appears to be offline." UserInfo={ _NSURLErrorNWPathKey = satisfied (Path is satisfied), interface: en0[802.11], ipv4, dns, uses wifi, LQM: good, NSErrorFailingURLKey = https://<my-pir-server>/config, NSUnderlyingError = { Error Domain=NSPOSIXErrorDomain Code=50 "Network is down" }, _NSURLErrorPrivacyProxyFailureKey = true, NSLocalizedDescription = "The Internet connection appears to be offline." } The critical diagnostic line in the com.apple.network subsystem is: nw_endpoint_proxy_handler_should_use_proxy Proxies not present, but required to fail closed And the connection setup shows the proxy fail closed flag is mandatory for the connection: [C... ... Hostname#...:443 quic, bundle id: <my-bundle-id>, attribution: developer, using ephemeral configuration, context: NWURLSession (sensitive), proxy fail closed] start The network path itself is healthy (Wi-Fi good, DNS resolves correctly), but the connection is explicitly configured to fail closed if no proxy is present, and no proxy is provisioned for this bundle identifier. The entire failure happens in approximately 18 ms, far too fast for any network round-trip, confirming no traffic ever leaves the device. What I've Verified The entitlement is present in the distribution build The NEURLFilterControlProvider extension loads and returns a valid Bloom filter prefilter (with a tag that round-trips correctly between extension and framework) NEURLFilterManager.setConfiguration(pirServerURL:pirPrivacyPassIssuerURL:pirAuthenticationToken:controlProviderBundleIdentifier:) accepts all four parameters without error Development-signed builds of the same bundle identifier connect successfully to the same PIR server On production-signed builds, zero requests reach the PIR server — failure is purely client-side, before any network activity The Question How does the OHTTP privacy proxy get provisioned for a bundle identifier so that production builds can successfully use NEURLFilter? Specifically: Is there a Capability Request form I need to submit for url-filter-provider? I cannot find one in the Capability Requests section of my developer portal. Should I be running my own OHTTP gateway (for example using swift-nio-oblivious-http), and if so, does Apple then need to provision routing from their OHTTP relay to my gateway URL? Is the OHTTP relay path meant to be automatic once the entitlement is active, and if so, is there a specific activation step I'm missing? Is there any way to verify the current provisioning state for a specific bundle identifier from the developer portal? I can provide the full sysdiagnose and unredacted bundle/server details privately to an Apple engineer if that would help diagnose. I'd prefer to keep them out of a public post. Thanks!
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Can an e-commerce iOS app running in the Xcode Simulator disrupt NETransparentProxyProvider and NEFilterDataProvider, causing DNS failures on macOS
Description: We are investigating an issue where running a specific e-commerce iOS app inside the Xcode Simulator intermittently disrupts the Mac’s network connectivity. When the app is launched in the Simulator, our NETransparentProxyProvider and NEFilterDataProvider extensions occasionally stop receiving traffic correctly, and shortly afterward the entire macOS DNS resolution fails. Once this happens, all apps on the Mac lose internet access until mac is restarted. Disabling extensions also fixing the issue. This issue only appears when the app runs in the Xcode Simulator. I would like to confirm: Is it possible for traffic patterns or network behavior inside the Simulator to interfere with system-level Network Extension providers on macOS? Are there known limitations or conflicts between the Simulator’s virtual networking interfaces and Network Extensions? Any recommended debugging steps or best practices to isolate this behavior? Any guidance, known issues, or suggestions would be appreciated.
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Dec ’25
Regression / Feature Request: Jumbo Frame (MTU 9000) support missing in AppleUserECM for RTL8156 2.5G USB adapters
Hello, I am currently developing a headless macOS daemon (HarmonBridge) that requires extremely low-latency, high-bandwidth UDP video streaming between a Mac and a Linux host over a dedicated 2.5GbE/5GbE local network link. We are utilizing widely available Realtek RTL8156 / RTL8156B based USB 2.5G network adapters. Under macOS, these adapters default to the generic com.apple.DriverKit.AppleUserECM driver. The hardware itself natively supports Jumbo Frames (MTU 9000), but the DriverKit implementation artificially restricts the MTU cap to 1500 bytes. Because we are forced through MTU 1500, we are incurring significant performance penalties: Excessive IP fragmentation for our large UDP video payloads. Unnecessary CPU overhead due to increased hardware interrupts and header processing at 2.5Gbps speeds. For a latency-critical application like ours, reducing CPU interrupts and utilizing true hardware-level Jumbo Frames is essential. My Questions: Is there an undocumented boot-arg or network sysctl parameter that permits overriding the AppleUserECM 1500 MTU hard-limit for 2.5G USB adapters on Apple Silicon? Are there any roadmap plans from the DriverKit/Networking team to re-enable standard Jumbo Frame negotiation for RTL8156 hardware using the generic ECM driver? If the answer to both is no, does Apple grant NetworkingDriverKit Entitlements to independent developers specifically for the purpose of writing custom hardware overrides to patch missing MTU features in the default ECM stack? Because AppleUserECM effectively acts as a gatekeeper to the underlying MAC/PHY capabilities of these modern USB NICs, any guidance on achieving wire-native MTU 9000 under the current DriverKit paradigm would be hugely appreciated. Thank you!
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`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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DHCP broken when device wakeup
Many times the device totally lost connectivity, WIFI is completely down, no ip was assigned after device wakeup. From system log I can see BPF socket for DHCP was closed and detached right after attached to en0 in DHCP INIT phase, as result even the DHCP server sent back OFFER(I see server sent OFFER back from packet capture), but there is no persistent BPF socket since it is closed reception during the entire INIT phase. It is definitely an OS issue, is it a known issue? Please help understand Why BPF socket was close right after sending DISCOVER? Default 0x0 0 0 kernel: bpf26 attached to en0 by configd:331 2026-03-25 14:06:33.625851+0100 0x31dea Default 0x0 0 0 kernel: bpf26 closed and detached from en0 fcount 0 dcount 0 by configd:331 System log and packet capture attach, please check.
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12
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0
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254
Activity
6d
Inquiries regarding telecommunications company codes
Hello, is there a way to get MCC/MNC carrier codes on iOS? I'm also wondering if there's a private API. I want to obtain network information while I am abroad to determine the country of residence.
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2
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0
Views
121
Activity
Jan ’26
NWConnectionGroup with Both Datagram and Non-datagram streams
I want to know the right way/API/usage to use NWConnectionGroup to send both datagram and non-datagram stream. I am currently working on an P2P video streaming app. I want to leverage NWConnectionGroup over QUIC to handle both message channel (traditionally handled by a TCP connection) and media channel (traditionally handled by sth. over UDP) to transmit SRT packets back and forth. I created a NWConnectionGroup and it worked fine on non-datagram parts. The problems are with datagram part. I tried extracting a connection with datagram = true either from the group or from message, doesn't and in some cases it breaks other non-datagram connections. I currently send datagram directly using the NWConnectionGroup.send(content:completion). It kinda works but I keep seeing it canceled a lot of messages, which breaks SRT shortly after start. The warnings belong flooded my console. (Seems like want me to create a connection to transmit datagram, how?) nw_connection_create_with_connection [C1600] Original connection not yet connected nw_connection_group_create_connection_for_endpoint_and_parameters [G1] failed to create connection with parameters quic, local: fe80::439:68b4:6ec2:694%en0.60517, definite, attribution: developer, server I must use it in wrong way. What should I do to fix it?
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1
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0
Views
132
Activity
Jan ’26
Number of Network Extension Limitations of future macOS
I haven’t come across any official documentation regarding the limit on the number of Network Extensions macOS can run. However, I did see some discussions suggesting that Apple might restrict this to 5 extensions in macOS Tahoe. Is there any official confirmation on this?
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4
Boosts
0
Views
338
Activity
Mar ’26
Why nslookup dns queries not routed to NETransparentProxyProvider
I’m using an NETransparentProxyProvider where I add UDP-53 rules to intercept DNS queries from a private application. These queries are resolved locally on the endpoint by returning a custom DNS response. Example Rules look like this: NENetworkRule(destinationHost: NWHostEndpoint(hostname: "mypaapp.com", port: 53),protocol:.UDP) This works as expected through browser and ping. handleNewUDPFlow/handleNewFlow with NEAppProxyUDPFlow gets called where custom dns response get written. Using nslookup mypaapp.com doesn't works. Why does this behaves differently for nslookup?
Replies
1
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0
Views
122
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?
Replies
5
Boosts
1
Views
2.1k
Activity
May ’25
System Information in macOS 26.2 RC no longer shows Wi-Fi SSIDs
System Information in macOS from 26.0 to 26.2 RC no longer provides Wi-Fi SSIDs; instead, it displays "< redacted> " for every SSID on my two MacBooks. This issue has been fixed in macOS 26.1 beta and macOS 26.2 beta, but it returns in the RC and the Final Release versions. Is it an expected behaviour or a bug in the Release Candidate? MacBook Air 2025: MacBook Pro 2021:
Replies
1
Boosts
0
Views
225
Activity
Dec ’25
An error occurred when downloading a background assets packs hosted by Apple.
On macOS Tahoe26.0, iOS 26.0 (23A5287g), Xcode 26.0 beta 3 (17A5276g) 1、Follow this tutorial Downloading asset packs hosted by Apple When i download a background asset packs hosted by Apple, Xcode callback "Download failed: The helper received an invalid server response with the status code “400”." Before downloading, I uploaded the three aar files to the Apple server using the Transporter app. Three Manifest.json content is: {"assetPackID":"bdassets2","downloadPolicy":{"onDemand":{}},"fileSelectors":[{"file":"1.jpg"},{"file":"2.pag"},{"file":"3.mp4"}],"platforms":["iOS"]} and {"assetPackID":"bdassets1","downloadPolicy":{"prefetch":{"installationEventTypes":["firstInstallation","subsequentUpdate"]}},"fileSelectors":[{"file":"1.jpg"},{"file":"2.pag"},{"file":"3.mp4"},{"directory":"a1"}],"platforms":["iOS"]} and {"assetPackID":"bdassets0","downloadPolicy":{"essential":{"installationEventTypes":["firstInstallation","subsequentUpdate"]}},"fileSelectors":[{"file":"1.jpg"},{"file":"2.pag"},{"file":"3.mp4"},{"directory":"a1"}],"platforms":["iOS"]} The same error was reported when the three aar files were obtained. I obtained it using the following code: do {       let assetPack = try await AssetPackManager.shared.assetPack(withID: "bdassets2")       try await AssetPackManager.shared.ensureLocalAvailability(of: assetPack)     } catch {       print("Download failed:", error)     } 2、Follow this tutorial Testing your asset packs locally I use this command line to start the test server:xcrun ba-serve --host 172.17.9.62 bdassets2.aar, The content displayed on the terminal is: Loading asset packs… Loading the asset pack at “bdassets2.aar”… Choose an identity in the panel to continue. Listening on port 56061… When running the project, Xcode reports an error:Download failed: Could not connect to the server. I use iPhone directly visit this website: https://172.17.9.62:56061, on the page display "Hello, world!" There are too few error messages in both of the above questions. I have no idea what the specific reasons are.I hope someone can offer some guidance. Best Regards.
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319
Activity
Jul ’25
joinAccessoryHotspot does not fail if wrong passphrase is provided
I am trying to connect to an accessory's WiFi network using the below code and I always see the message "connection succeded" even if I provide an incorrect passphrase. I tried with different accessories and see the same behavior. hotspotConfigurationManager.joinAccessoryHotspot(accessory, passphrase: passphrase) { error in if let error = error { print("connection failed: \(error.localizedDescription)") } else { print("connection succeeded") } }
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2
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167
Activity
Apr ’25
Disable Local Network Access permission check
I'm using a Mac Studio in a homelab context and use Homebrew to manage the installed services. The services include things that access the local network, for example Prometheus which monitors some other servers, a reverse proxy which fronts other web services on the network, and a DNS server which can use another as upstream. Local Network Access permissions make it impossible to reliably perform unattended updates of services because an updated binary requires a GUI login to grant local network permissions (again). I use brew services to manage the services as launchd agents, i.e. they run in a non-root GUI context. I know that I can also use sudo brew services which instead installs the services as launchd daemons, but running services as root has negative security implication and generally doesn't look like a good idea to me. If only there was a way to disable local network access checks altogether…
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11
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425
Activity
Feb ’26
The iOS 26 simulator crashed due to NWPathMonitor
Simulator: iPhone 16 pro (iOS 26) Minimum Deployments: iOS 16.0+, not iOS 17. Here is the demo: import SwiftUI import NetworkExtension struct ContentView: View { private var monitor = NWPathMonitor() var body: some View { VStack { Text("Hello, world!") } .task { let _ = URLSession.shared } } }
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345
Activity
Jun ’25
Replacing Packet Filter (pf) with Content Filter for VPN Firewall Use Case
Hi, We're in the process of following Apple’s guidance on transitioning away from Packet Filter (pf) and migrating to a Network Extension-based solution that functions as a firewall. During this transition, we've encountered several limitations with the current Content Filter API and wanted to share our findings. Our VPN client relies on firewall functionality to enforce strict adherence to split tunneling rules defined via the routing table. This ensures that no traffic leaks outside the VPN tunnel, which is critical for our users for a variety of reasons. To enforce this, our product currently uses interface-scoped rules to block all non-VPN traffic outside the tunnel. Replicating this behavior with the Content Filter API (NEFilterDataProvider) appears to be infeasible today. The key limitation we've encountered is that the current Content Filter API does not expose information about the network interface associated with a flow. As a workaround, we considered using the flow’s local endpoint IP to infer the interface, but this data is not available until after returning a verdict to peek into the flow’s data—at which point the connection has already been established. This can result in connection metadata leaking outside the tunnel, which may contain sensitive information depending on the connection. What is the recommended approach for this use case? NEFilterPacketProvider? This may work, but it has a negative impact on network performance. Using a Packet Tunnel Provider and purely relying on enforceRoutes? Would this indeed ensure that no traffic can leak by targeting a specific interface or by using a second VPN extension? And more broadly—especially if no such approach is currently feasible with the existing APIs—we're interpreting TN3165 as a signal that pf should be considered deprecated and may not be available in the next major macOS release. Is that a reasonable interpretation?
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275
Activity
May ’25
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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381
Activity
Feb ’26
Wi-Fi connectivity Issue - Captive.apple.com returns “application/octet-stream” instead of “text/html”,
In our system, when a user enables a mobile hotspot and the system connects to it, the system attempts to verify WIFI availability by sending an HTTP GET request to http://captive.apple.com. Normally, the server returns: HTTP Status: 200 (OK) Content-Type: text/html This has always been used as a sign of normal connectivity. Issue: Since last Friday, the server sometimes responds with: Content-Type: application/octet-stream When this occurs, our system determines that the network is unavailable and displays a connection warning (a “!” icon). Question: Has Apple recently made any backend or CDN configuration changes to captive.apple.com that could affect the response type? Any advice how can we solve this problem? Thanks!
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3
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1k
Activity
Jan ’26
Didn't receive any notification from coreWLAN for linkQualityDidChange
https://developer.apple.com/documentation/corewlan/cweventtype/linkqualitydidchange As per the documentation core WLAN will send notification when there is a change in RSSI. I did not receive any notification when there is a change in RSSI.
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189
Activity
1w
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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113
Activity
2w
NEURLFilter production build fails with _NSURLErrorPrivacyProxyFailureKey — how to provision OHTTP privacy proxy for bundle?
Summary I'm implementing NEURLFilter with the com.apple.developer.networking.networkextension.url-filter-provider entitlement for a system-wide URL filtering feature. The feature works perfectly in development-signed builds (connecting successfully to my PIR server over extended testing) but every production-signed build fails before any network call is made. NEURLFilterManager reports .serverSetupIncomplete (code 9). After installing the NetworkExtension debug profile, the unredacted com.apple.CipherML logs reveal the cause: no privacy proxy is provisioned for this bundle identifier, and the connection is configured proxy fail closed. Environment iOS 26 Entitlement: com.apple.developer.networking.networkextension.url-filter-provider Extension point: com.apple.networkextension.url-filter-control PIR server configured via NEURLFilterManager.setConfiguration(...) Privacy Pass issuer configured Dev-signed builds: working correctly, connecting to the PIR server Production-signed builds (both TestFlight and distribution): failing identically The Error Chain Surfaced to the app via NEURLFilterManager.lastDisconnectError: NEURLFilterManager.Error.serverSetupIncomplete (code 9) ← NEAgentURLFilterErrorDomain Code 3 ← com.apple.CipherML Code 1100 "Unable to query status" ← com.apple.CipherML Code 1800 (error details were logged and redacted) After installing the VPN (NetworkExtension) debug profile, the unredacted com.apple.CipherML subsystem shows: queryStatus(for:options:) threw an error: Error Domain=NSURLErrorDomain Code=-1009 "The Internet connection appears to be offline." UserInfo={ _NSURLErrorNWPathKey = satisfied (Path is satisfied), interface: en0[802.11], ipv4, dns, uses wifi, LQM: good, NSErrorFailingURLKey = https://<my-pir-server>/config, NSUnderlyingError = { Error Domain=NSPOSIXErrorDomain Code=50 "Network is down" }, _NSURLErrorPrivacyProxyFailureKey = true, NSLocalizedDescription = "The Internet connection appears to be offline." } The critical diagnostic line in the com.apple.network subsystem is: nw_endpoint_proxy_handler_should_use_proxy Proxies not present, but required to fail closed And the connection setup shows the proxy fail closed flag is mandatory for the connection: [C... ... Hostname#...:443 quic, bundle id: <my-bundle-id>, attribution: developer, using ephemeral configuration, context: NWURLSession (sensitive), proxy fail closed] start The network path itself is healthy (Wi-Fi good, DNS resolves correctly), but the connection is explicitly configured to fail closed if no proxy is present, and no proxy is provisioned for this bundle identifier. The entire failure happens in approximately 18 ms, far too fast for any network round-trip, confirming no traffic ever leaves the device. What I've Verified The entitlement is present in the distribution build The NEURLFilterControlProvider extension loads and returns a valid Bloom filter prefilter (with a tag that round-trips correctly between extension and framework) NEURLFilterManager.setConfiguration(pirServerURL:pirPrivacyPassIssuerURL:pirAuthenticationToken:controlProviderBundleIdentifier:) accepts all four parameters without error Development-signed builds of the same bundle identifier connect successfully to the same PIR server On production-signed builds, zero requests reach the PIR server — failure is purely client-side, before any network activity The Question How does the OHTTP privacy proxy get provisioned for a bundle identifier so that production builds can successfully use NEURLFilter? Specifically: Is there a Capability Request form I need to submit for url-filter-provider? I cannot find one in the Capability Requests section of my developer portal. Should I be running my own OHTTP gateway (for example using swift-nio-oblivious-http), and if so, does Apple then need to provision routing from their OHTTP relay to my gateway URL? Is the OHTTP relay path meant to be automatic once the entitlement is active, and if so, is there a specific activation step I'm missing? Is there any way to verify the current provisioning state for a specific bundle identifier from the developer portal? I can provide the full sysdiagnose and unredacted bundle/server details privately to an Apple engineer if that would help diagnose. I'd prefer to keep them out of a public post. Thanks!
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1w
Can an e-commerce iOS app running in the Xcode Simulator disrupt NETransparentProxyProvider and NEFilterDataProvider, causing DNS failures on macOS
Description: We are investigating an issue where running a specific e-commerce iOS app inside the Xcode Simulator intermittently disrupts the Mac’s network connectivity. When the app is launched in the Simulator, our NETransparentProxyProvider and NEFilterDataProvider extensions occasionally stop receiving traffic correctly, and shortly afterward the entire macOS DNS resolution fails. Once this happens, all apps on the Mac lose internet access until mac is restarted. Disabling extensions also fixing the issue. This issue only appears when the app runs in the Xcode Simulator. I would like to confirm: Is it possible for traffic patterns or network behavior inside the Simulator to interfere with system-level Network Extension providers on macOS? Are there known limitations or conflicts between the Simulator’s virtual networking interfaces and Network Extensions? Any recommended debugging steps or best practices to isolate this behavior? Any guidance, known issues, or suggestions would be appreciated.
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407
Activity
Dec ’25
Regression / Feature Request: Jumbo Frame (MTU 9000) support missing in AppleUserECM for RTL8156 2.5G USB adapters
Hello, I am currently developing a headless macOS daemon (HarmonBridge) that requires extremely low-latency, high-bandwidth UDP video streaming between a Mac and a Linux host over a dedicated 2.5GbE/5GbE local network link. We are utilizing widely available Realtek RTL8156 / RTL8156B based USB 2.5G network adapters. Under macOS, these adapters default to the generic com.apple.DriverKit.AppleUserECM driver. The hardware itself natively supports Jumbo Frames (MTU 9000), but the DriverKit implementation artificially restricts the MTU cap to 1500 bytes. Because we are forced through MTU 1500, we are incurring significant performance penalties: Excessive IP fragmentation for our large UDP video payloads. Unnecessary CPU overhead due to increased hardware interrupts and header processing at 2.5Gbps speeds. For a latency-critical application like ours, reducing CPU interrupts and utilizing true hardware-level Jumbo Frames is essential. My Questions: Is there an undocumented boot-arg or network sysctl parameter that permits overriding the AppleUserECM 1500 MTU hard-limit for 2.5G USB adapters on Apple Silicon? Are there any roadmap plans from the DriverKit/Networking team to re-enable standard Jumbo Frame negotiation for RTL8156 hardware using the generic ECM driver? If the answer to both is no, does Apple grant NetworkingDriverKit Entitlements to independent developers specifically for the purpose of writing custom hardware overrides to patch missing MTU features in the default ECM stack? Because AppleUserECM effectively acts as a gatekeeper to the underlying MAC/PHY capabilities of these modern USB NICs, any guidance on achieving wire-native MTU 9000 under the current DriverKit paradigm would be hugely appreciated. Thank you!
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161
Activity
2w
`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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146
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2w