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, I have a problem with my Mac crashing sims 4. can you let me know if this is a Mac problem or a sims 4 problem ? Link to Mac Info : https://prnt.sc/NYG0jn8_u0dB Link to crash report : https://prnt.sc/UImzDIsqdVYn

With the new macOS 15, Apple introduced the new Local Network Privacy feature. This is causing issues for our customers as - even though they granted the required permission for our software - connections to a server in their local network are being blocked. The situation is not fixed by recent macOS updates. As far as I know, this issue exists for machines running on Apple Silicon. Systems running macOS versions (e.g. Sonoma) are not affected. Currently, the workaround is to re-enable the permission under Settings > Privacy & Security > Local Network. The list shows our application with an enabled checkbox. Users now have to de-select the box and then re-select it again for the application to work. They have to do this after each and every reboot of their system, which is slightly annoying (so at the moment we recommend to not upgrade macOS to Sequoia, if possible) I did some research and saw that other products are also affected by this bug. Is there a solution to this issue or any plans to fix it?

I'm writing a SwiftUI LDAP Browser. I built a command line swift app to do some testing and it works fine. I had to add the certificates from the LDAP server to the system keychain before it would work with TLS/SSL. Then I ported the same code into a SwiftUI app but I cannot get it to connect via TLS/SSL. On the same machine with the same certs it errors with: An unexpected error occurred: message("Can't contact LDAP server") It connect fine with our TLS/SSL. I suspect this may have to do with App Transport Security. Can anyone point me in the right direction to resolve this? App is MacOS only.

We updated the apple-app-site-association file two weeks ago and we are only seeing the new content from Apple's CDN serving certain regions such as Texas and Canada. Regions such as Colorado intermittently sees the old content and California has been receiving the old content all the time. Is this a known issue? If yes, when can we expect this to be fixed and where to check the status? If not, can someone in charge of CDN please look into this? Let me know if there is a better place to report this issue and get the support ASAP though. Thank you in advance and happy new year!

I was wondering if anybody knows if it's possible for an app to use a QR code to join a Wi-Fi network - the same functionality as the iOS 11 Camera app?I have some code reading a QR Code that looks something like - "WIFI:S:name-of-network;T:WPA;P:password;;"This QR code works perfectly in the native camera app - asking the user if they'd like to join the Wi-Fi network and successfully joining if they do.When I scan the QR code in my own code, I get the following error: canOpenURL: failed for URL: "WIFI:S:name-of-network;T:WPA;P:password;;" - error: "The operation couldn’t be completed. (OSStatus error -10814.)"In my app, I've got URL Schemes for "prefs" and have added "wifi" in LSApplicationQueriesSchemes.Am I doing something wrong, or is this simply not possible?If it's not possible, is there anyway to use the iOS native camera functionality within an app?

On macOS 15, if a program installed in /Applications is allowed to connect to a PostgreSQL server on another machine on the local network, a program launched in debug mode from Xcode is not allowed to connect to the local network, and no prompt appears. Although it is possible to turn off registered programs in Local Network Privacy in Beta 2, permissions for programs launched from Xcode cannot be obtained at all. Does anyone know how to solve this problem?

I'm trying to detect the state of Local Network privacy on macOS Sequoia via NWBrowser, as recommended in https://developer.apple.com/documentation/technotes/tn3179-understanding-local-network-privacy Regardless of the state of Local Network privacy - undetermined, allowed or denied, NWBrowser receives an update indicating that its in the ready state. Scanning does not seem to trigger the Local Network privacy alert for me - I have to use the other recommended method to trigger the prompt. Enabling or disabling Local Network privacy does not seem to send any updates for NWBrowser. https://developer.apple.com/forums/thread/666431 seems related, and implies that they did receive further updates to NWBrowser. Filed as FB16077972

I've implemented a custom VPN for macOS (system extension, Packet Tunnel Provider, Developer ID). My tunneling logic uses BSD sockets. My VPN is configured with on-demand and should always connect when there's traffic: targetManager?.isOnDemandEnabled = true targetManager?.onDemandRules = [NEOnDemandRuleConnect()] I have encountered some issues when the device enters sleep (or waking up from sleep). I've tried two scenarios. Scenario 1: protocolConfiguration?.disconnectOnSleep = true With this flag set, the OS will disconnect the VPN just before entering to sleep. However, there were cases when the OS disconnected the VPN but immediately restarted it - probably because of how I defined the on-demand rules. This resulted in the VPN disconnection, then trying to reconnect, and then the Mac entered sleep. When the Mac woke up, the VPN didn't work well. Is there a way to avoid waking up, just before the Mac enters sleep? Scenario 2: protocolConfiguration?.disconnectOnSleep = false Disconnect on sleep is unset, and I've implemented the sleep/wake functions at the provider. With this configuration, the OS won't disconnect the VPN, so even in sleep, the extension should stay 'alive,' so it won't have the problem from (1). But in this case, I had other problems: On sleep, I'm disconnecting the tunnel. But sometimes, on wake(), all my network calls fail. Are the interfaces still down? How can I detect this case from the system extension? Is it possible that the OS would call sleep and then quickly call wake? Is it possible that after sleep, the OS would call the startTunnelWithOptions() function? Is it possible to restart the extension from a clean state right from the wake() function?

I was trying to log the flow description using control filter and data filter. But when I am trying to log the proc ID in control filter, it is always 0, but in data filter, it logs some value. Same goes with the eproc ID. I want to use the flow description data in some other target so I will be sending the data using sockets and I cannot share data from data filter due to its restrictions and control filter isn't providing the proc ID. What should I do?

Hi, I have a problem with my OpenVPN connection on my app with iOS 14.4. I perform my VPN configuration from an oven file, with a NETunnelProviderManager protocol, but when I perform the startVPNTunnel, it starts connecting and immediately disconnects. The error I see in the logs is the following: NESMVPNSession[Primary Tunnel:OpenVPN Client: -----(null)]: status changed to disconnected, last stop reason Plugin was disabled This happens to me when running my app on a physical iPad. Regards import NetworkExtension import OpenVPNAdapter class VPNConnection {          var connectionStatus = "Disconnected"              var myProviderManager: NETunnelProviderManager?          func manageConnectionChanges( manager:NETunnelProviderManager ) - String {         NSLog("Waiting for changes");         var status = "Disconnected"                  NotificationCenter.default.addObserver(forName: NSNotification.Name.NEVPNStatusDidChange, object: manager.connection, queue: OperationQueue.main, using: { notification in                          let baseText = "VPN Status is "                          switch manager.connection.status {             case .connected:                 status = "Connected"             case .connecting:                 status = "Connecting"             case .disconnected:                 status = "Disconnected"             case .disconnecting:                 status = "Disconnecting"             case .invalid:                 status = "Invalid"             case .reasserting:                 status = "Reasserting"             default:                 status = "Connected"             }                          self.connectionStatus = status                          NSLog(baseText+status)                      });         return status     }          func createProtocolConfiguration() - NETunnelProviderProtocol {         guard             let configurationFileURL = Bundle.main.url(forResource: "app-vpn", withExtension: "ovpn"),             let configurationFileContent = try? Data(contentsOf: configurationFileURL)         else {             fatalError()         }                  let tunnelProtocol = NETunnelProviderProtocol()         tunnelProtocol.serverAddress = ""         tunnelProtocol.providerBundleIdentifier = "com.app.ios"                  tunnelProtocol.providerConfiguration = ["ovpn": String(data: configurationFileContent, encoding: .utf8)! as Any]         tunnelProtocol.disconnectOnSleep = false                  return tunnelProtocol     }          func startConnection(completion:@escaping () - Void){         self.myProviderManager?.loadFromPreferences(completionHandler: { (error) in             guard error == nil else {                 // Handle an occurred error                 return             }                          do {                 try self.myProviderManager?.connection.startVPNTunnel()                 print("Tunnel started")             } catch {                 fatalError()             }         })     }          func loadProviderManager(completion:@escaping () - Void) {                           NETunnelProviderManager.loadAllFromPreferences { (managers, error) in             guard error == nil else {                 fatalError()                 return             }                          self.myProviderManager = managers?.first ?? NETunnelProviderManager()             self.manageConnectionChanges(manager: self.myProviderManager!)                          self.myProviderManager?.loadFromPreferences(completionHandler: { (error) in                 guard error == nil else {                     fatalError()                     return                 }                                  let tunnelProtocol = self.createProtocolConfiguration()                                  self.myProviderManager?.protocolConfiguration = tunnelProtocol                 self.myProviderManager?.localizedDescription = "OpenVPN Client Ubic"                                  self.myProviderManager?.isEnabled = true                                  self.myProviderManager?.isOnDemandEnabled = false                                  self.myProviderManager?.saveToPreferences(completionHandler: { (error) in                     if error != nil  {                         // Handle an occurred error                         fatalError()                     }                     self.startConnection {                         print("VPN loaded")                     }                 })             })         }     } }

I was trying to fetch inBytes and outBytes in content filter. Each time it is logging 0 as inByte and outByte in handleNewFlow flow description. How to get inByte and outByte of the flow?

Didn't get any response last time so reposting my query. I know procID is of no use in IOS but just for curiosity I am logging proc ID in control Filter and data Filter. I was trying to log the flow description using control filter and data filter. But when I am trying to log the proc ID in control filter, it is always 0, but in data filter, it logs some value. Same goes with the eproc ID. I want to use the flow description data in some other target so I will be sending the data using sockets and I cannot share data from data filter due to its restrictions and control filter isn't providing the proc ID. What should I do?

Crash within com.apple.CFNetwork.Connection , specifically due to EXC_BAD_ACCESS KERN_INVALID_ADDRESS. The crash occurred within the nghttp2_session_del() function indicating a problem with the nghttp2 library, which is commonly used for HTTP/2 communication. This points towards a memory management issue. EXC_BAD_ACCESS generally signifies that the application attempted to access memory it didn't have permission to access, often caused by using a pointer after it has been freed or pointing to an invalid memory address. ** Crashed: com.apple.CFNetwork.Connection 0 libapple_nghttp2.dylib 0xa6ec nghttp2_session_del + 124 1 CFNetwork 0xace4c + 428 2 CFNetwork 0xacc80 + 36 3 libdispatch.dylib 0x2370 _dispatch_call_block_and_release + 32 4 libdispatch.dylib 0x40d0 _dispatch_client_callout + 20 5 libdispatch.dylib 0xb6d8 _dispatch_lane_serial_drain + 744 6 libdispatch.dylib 0xc214 _dispatch_lane_invoke + 432 7 libdispatch.dylib 0xd670 _dispatch_workloop_invoke + 1732 8 libdispatch.dylib 0x17258 _dispatch_root_queue_drain_deferred_wlh + 288 9 libdispatch.dylib 0x16aa4 _dispatch_workloop_worker_thread + 540 10 libsystem_pthread.dylib 0x4c7c _pthread_wqthread + 288 11 libsystem_pthread.dylib 0x1488 start_wqthread + 8 ** The stack trace does not point to any code within our product codebase, hence making it difficult to pinpoint the root cause of the issue as there are multiple network calls running concurrently during the app's runtime.

NEFilterManager.shared().loadFromPreferences { loadError in DispatchQueue.global.async { ... } } the code above is executed in an app-like deamon and completionHandler was never invoked, same code in an application works fine.(they are both packed with content filter network system extension) is it because of the restriction of app-like deamon?

If an app has a text filtering extension and associated server that the iPhone OS communicates with, then how can that communication be authenticated? In other words, how can the server verify that the request is valid and coming from the iPhone and not from some spoofer? If somebody reverse engineers the associated domain urls our of the app's info.plist or entitlement files and calls the server url directly, then how can the server detect this has occurred and the request is not coming from the iPhone OS of a handset on which the app is installed?

Hi everyone, We are working on creating a virtual network interface using NEPacketTunnelProvider, with an MTU of 1500 bytes. I would like to understand what will happen if we attempt to write packets of approximately 65,000 bytes to this interface. Specifically, will the packets be fragmented based on protocol and flags, will they be dropped, or is there another unexpected behaviour we should anticipate? Thanks

Case-ID: 10969723 （Due to privacy concerns, I have hidden part of the URL and included the complete plain text in the email demo project with Case-ID: 10969723） After our game was launched in Japan, a small number of Japanese users reported that they were unable to enter the game. After our investigation, we confirmed that the request under the yfy-api-oversea.xxxxxxxxxxxxxx.com domain name failed. iOS NSURLSession API returns the following error: Error Domain=NSURLErrorDomain Code=-1000 "無効なURL" UserInfo={_kCFStreamErrorCodeKey=22, NSUnderlyingError=0x3019e8030 {Error Domain=kCFErrorDomainCFNetwork Code=-1000 "(null)" UserInfo={_NSURLErrorNWPathKey=satisfied (Path is satisfied), interface: en0[802.11], ipv4, ipv6, dns, proxy, uses wifi, _kCFStreamErrorCodeKey=22, _kCFStreamErrorDomainKey=1}}, _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask .<7>, _NSURLErrorRelatedURLSessionTaskErrorKey=( "LocalDataTask .<7>" ), NSLocalizedDescription=無効なURL, NSErrorFailingURLStringKey=https://yfy-api-oversea.xxxxxxxxxxxxxx.com/init/info?channel_code=jpxxxxxxxxxxxxxxios&timestamp=1735012505&sign=1617e4cf88b58df2aa90a6b3985a8ac2&game_code=XXXXX, NSErrorFailingURLKey=https://yfy-api-oversea.xxxxxxxxxxxxxx.com/init/info?channel_code=jpxxxxxxxxxxxxxxios&timestamp=1735012505&sign=1617e4cf88b58df2aa90a6b3985a8ac2&game_code=XXXXX, _kCFStreamErrorDomainKey=1}。 We have tried various methods but cannot reproduce this error (Code=-1000). I can provide the following clues： 1、We have checked the server and confirmed that the request did not reach the server, but was intercepted by the iOS client and was not sent. 2、This problem does not seem to have much to do with the iOS system version. The system versions where the problem occurred are widely distributed: 17.2.1、17.7.1、17.5.1、17.6.1、17.7、18.0.1、18.1、18.1.1 e.g. 3、This problem seems to have nothing to do with the device model. The following models have experienced problems: iPhone16、iPhone 16 Pro、iPhone 14、iPhone 14 Plus、iPhone 14 Pro Max、iPhone 13、iPhone11 e.g. 4、By tracking the logs, some users who encountered the problem later recovered and the problem did not occur again（The user IP and iOS system restored by yourself have not changed）. However, this problem persists for some users. Even if the iOS system is upgraded to the latest version, there are still problems. 5、The following two IPs are the IPs of users who encountered this problem (1.73.13.210, 153.252.131.136). But this problem seems to have nothing to do with IP. For some users who restored themselves, their IPs did not change, but the problem no longer occurred. 6、This problem seems to only occur in Japan. Mainland China, Taiwan, and Hong Kong have never encountered this situation. 7、It doesn't seem to have anything to do with GET requests. Another login request（https://yfy-api-oversea.xxxxxxxxxxxxxx.com/login/c/place）uses a POST request and will also encounter this error. 8、I wonder if it has something to do with the two symbol "-" in the domain name? I checked Apple documentation and searched online, but couldn't find any more information. This problem cannot be reproduced either. Only technical requests can be initiated. I provided a demo project(see email for Case-ID: 10969723) Thanks.

I've implemented a custom system extension VPN for macOS, using a Packet Tunnel Provider. I saw something suspicious on macOS 15.2.0: When I disconnected my VPN, the UTUN was not being cleared. This results in a lot of UTUNs when the user connects and disconnects multiple times. utun77: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500 utun78: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500 This happens only on macOS 15.2. I tried the same app on older versions (15.0, 15.1.x), and it didn't reproduce. Can those 'dirty' UTUNs cause a networking problem? Since it happens only on macOS 15.2, is there a bug in this OS version? How can I check if something in my code causes this behavior? How can I 'fix' it or force clean the 'dirty' UTUNs?

I want to check if the device has a internet connection or not by pinging DNS "8.8.8.8". connection.send(content: content, completion: .contentProcessed {[weak self] error in send function is not returning any error even if the host is unreachable. I am checking if I can receive the data or not but connection.receiveMessage function never returns. This is the complete code which I am following: private let networkMonitor = NWPathMonitor() private var connection: NWConnection @MainActor var isConnectedToInternet = false init(host: NWEndpoint.Host = "8.8.8.8", port: NWEndpoint.Port = 53) { let endpoint = NWEndpoint.hostPort(host: host, port: port) connection = NWConnection(to: endpoint, using: .udp) startMonitoring() } private func startMonitoring() { networkMonitor.pathUpdateHandler = { [weak self] path in guard let self else { return } ping(callback: { isSuccess in print("***** ping status:", isSuccess) Task { @MainActor in self.isConnectedToInternet = isSuccess } }) } let queue = DispatchQueue(label: QueueLabel.networkMonitor) networkMonitor.start(queue: queue) } func ping( host: NWEndpoint.Host = "8.8.8.8", port: NWEndpoint.Port = 53, callback: @escaping ((Bool) -> Void) ) { var didSendState = false connection.stateUpdateHandler = {[weak self] state in guard let self = self else { return } guard !didSendState else { if state != .cancelled { cancel(connection) } return } switch state { case .ready: // State is ready now send data let content = "Ping".data(using: .utf8) let startTime = Date() connection.send(content: content, completion: .contentProcessed {[weak self] error in guard let self = self else { return } if error != nil { callback(false) didSendState = true cancel(connection) } else { print("Ping sent, waiting for response...") connection.receiveMessage { [weak self] content, _, _, receiveError in guard let self = self else { return } if let receiveError { print("Error receiving ping: \(receiveError.localizedDescription)") callback(false) } else if let content = content, String(data: content, encoding: .utf8) == "Ping" { let roundTripTime = Date().timeIntervalSince(startTime) print("Ping received! Round-trip time: \(roundTripTime) seconds") callback(true) } else { print("Invalid response received") callback(true) } didSendState = true cancel(connection) } } }) case .failed( _), .waiting( _), .cancelled: didSendState = true callback(false) case .setup, .preparing: // No callback because the ping has not yet succeeded or failed break @unknown default: didSendState = true callback(false) // We don't know what this unknown default means, so cancel pings to be safe cancel(connection) } } connection.start(queue: .main) } func cancel(_ connection: NWConnection) { connection.cancel() } } Can anyone please help what I am doing wrong.

We have an app which is using CTSubscriber.simInserted (using the carrier entitlement com.apple.CommCenter.fine-grained). In iOS 18, simInserted returns false for every sim (where it should instead be returning true). Presumably this just is a temporary bug in 18 beta?