I have few API's written with URLSession. Will they work in Carrier-constrained network / satellite mode ?

I have 3 phones iPhone 14 iOS 18.3 iPhone Xr iOS 18.5 iPhone Xr iOS 18.4.1 My app has a network extension, and I've noticed each phone having their connectivity interupted by calls on the push provider, calling stop with the noNetworkAvailable reason. The point of confusion is that each phone seems to get it's interuption at different times. For example one will get an interuption at 1:00, while the others is fine, while at 3:00 another will get an interuption, while the others are fine. This is confusing since a "no network available" seems to imply a problem with the router, or access point, but if that were the case, one would believe it should affect all the phones on the wifi. I don't see less interuptions on the iPhone14 vs the iPhone Xr. Do you believe the iOS version is affecting the performance? Could you please give me some insight, as to what could be going on inside these phones? P.S. I also see an error pop up when using NWConnection, this is inside the App. The state update handler will sometimes return the state, waiting(POSIX(.ENETDOWN)) Is there any relation to what's going on in the extension?

We are developers of an app, we found that there's no LN prompt for users to install the app for the 1st time on ios18. We used the following method to prompt the "allow/not allow" alert: // Attempts to trigger the local network privacy alert. /// /// This builds a list of link-local IPv6 addresses and then creates a connected /// UDP socket to each in turn. Connecting a UDP socket triggers the local /// network alert without actually sending any traffic. /// /// This is a ‘best effort’ approach, and it handles errors by ignoring them. /// There’s no guarantee that it’ll actually trigger the alert (FB8711182). func triggerLocalNetworkPrivacyAlert() { let addresses = selectedLinkLocalIPv6Addresses() for address in addresses { let sock6 = socket(AF_INET6, SOCK_DGRAM, 0) guard sock6 >= 0 else { return } defer { close(sock6) } withUnsafePointer(to: address) { sa6 in sa6.withMemoryRebound(to: sockaddr.self, capacity: 1) { sa in _ = connect(sock6, sa, socklen_t(sa.pointee.sa_len)) >= 0 } } } }

We have an application which is written in Swift, which activates network extension (Transparent Proxy). We want to use MDM deployment for this network system extension. Our Transparent Proxy module is a system extension, which is exposing an app proxy provider interface (We are using NETransparentProxyProvider class and in extension’s Info.plist we use com.apple.networkextension.app-proxy key.) We don’t have any remote server setup to forward the traffic, instead we open a connection with a certain localhost:port to redirect the traffic which is received in our transparent proxy. We have another module that listens to the particular localhost:port to process the traffic further. As per https://developer.apple.com/documentation/devicemanagement/vpn/transparentproxy documentation, we noticed that we can use the VPN payload with app-proxy as Provider Type for Transparent Proxy. We were able to install the profile created via Jamf Pro and also while in stalling our product the Transparent Proxy gets mapped with the one which is installed via profile. However after that the network is broken and hence unable to browse anything. We are suspecting the remote server filed is causing this. So we tried creating the custom profile without remote server address for VPN payload, but we are unable to install the profile. It throws below error: 2025-02-11 16:43:55.193348+0530 0x2f880 Error 0x0 6815 0 mdmclient: (NetworkExtension) [com.apple.networkextension:] Failed to save configuration DGWebProxy because it is invalid: Error Domain=NEConfigurationErrorDomain Code=2 "configuration is invalid: Missing server address" UserInfo={NSLocalizedDescription=configuration is invalid: Missing server address}
2025-02-11 16:43:55.193376+0530 0x2f880 Error 0x0 6815 0 mdmclient: (NetworkExtension) [com.apple.networkextension:] NEProfileIngestion Error occurred when saving configuration 'DGWebProxy': configuration is invalid: configuration is invalid: Missing server address 
2025-02-11 16:43:55.196159+0530 0x2f880 Error 0x0 6815 7 mdmclient: [com.apple.ManagedClient:CPDomainPlugIn] [ERROR] [0:MDMDaemon:CPDomainPlugIn:<0x2f880>] <<<<< PlugIn: InstallPayload [NEProfileIngestionPlugin] Error: Error Domain=ConfigProfilePluginDomain Code=-319 "The ‘VPN Service’ payload could not be installed. The VPN service could not be created." UserInfo={NSLocalizedDescription=The ‘VPN Service’ payload could not be installed. The VPN service could not be created.} <<<<<
2025-02-11 16:43:55.196826+0530 0x2f880 Error 0x0 6815 7 mdmclient: [com.apple.ManagedClient:MDMDaemon] [ERROR] [0:MDMDaemon:<0x2f880>] [CE] PlugIn_InstallPayload ==> Error Domain=ConfigProfilePluginDomain Code=-319 "The ‘VPN Service’ payload could not be installed. The VPN service could not be created." UserInfo={NSLocalizedDescription=The ‘VPN Service’ payload could not be installed. The VPN service could not be created.} Can we create MDM profile for Transparent Proxy without remote server address?

Greetings I'm trying to get on iPad the SSID from the wifi I'm connected to. For that, I added the wifi entitlement and I'm requesting permission to the user for Location. Once I have it, I'm using the function CNCopySupportedInterfaces to get the interfaces, but I can only receive the en0, which using the method CNCopyCurrentNetworkInfo returns nil. I also tried using the NEHotspotNetwork.fetchCurrent and the SSID keeps being nil. So right now I'm drawing a blank. Is there any way to make it work? Thanks.

I'm creating a custom VPN app which should only work on Cellular. Apart from cellular interface binding VPN is working fine. Even though I specified cellular interface like let cellularParams = NWParameters.udp cellularParams.requiredInterfaceType = .cellular It is going via Wifi when it is ON. I know this is the default iOS behaviour. How can I prevent this and route through cellular only even when Wifi is enabled on device?

Hi, I’m trying to download a remote file in the background, but I keep getting a strange behaviour where URLSession download my file indefinitely during a few minutes, without calling urlSession(_:downloadTask:didFinishDownloadingTo:) until the download eventually times out. To find out that it’s looping, I’ve observed the total bytes written on disk by implementing urlSession(_:downloadTask:didWriteData:totalBytesWritten:totalBytesExpectedToWrite:). Note that I can't know the size of the file. The server is not able to calculate the size. Below is my implementation. I create an instance of URLSession like this: private lazy var session: URLSession = { let configuration = URLSessionConfiguration.background(withIdentifier: backgroundIdentifier) configuration.isDiscretionary = false configuration.sessionSendsLaunchEvents = true return URLSession(configuration: configuration, delegate: self, delegateQueue: nil) }() My service is using async/await so I have implemented an AsyncThrowingStream : private var downloadTask: URLSessionDownloadTask? private var continuation: AsyncThrowingStream&lt;(URL, URLResponse), Error&gt;.Continuation? private var stream: AsyncThrowingStream&lt;(URL, URLResponse), Error&gt; { AsyncThrowingStream&lt;(URL, URLResponse), Error&gt; { continuation in self.continuation = continuation self.continuation?.onTermination = { @Sendable [weak self] data in self?.downloadTask?.cancel() } downloadTask?.resume() } } Then to start the download, I do : private func download(with request: URLRequest) async throws -&gt; (URL, URLResponse) { do { downloadTask = session.downloadTask(with: request) for try await (url, response) in stream { return (url, response) } throw NetworkingError.couldNotBuildRequest } catch { throw error } } Then in the delegate : public func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) { guard let response = downloadTask.response, downloadTask.error == nil, (response as? HTTPURLResponse)?.statusCode == 200 else { continuation?.finish(throwing: downloadTask.error) return } do { let documentsURL = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false) let savedURL = documentsURL.appendingPathComponent(location.lastPathComponent) try FileManager.default.moveItem(at: location, to: savedURL) continuation?.yield((savedURL, response)) continuation?.finish() } catch { continuation?.finish(throwing: error) } } I also tried to replace let configuration = URLSessionConfiguration.background(withIdentifier: backgroundIdentifier) by let configuration = URLSessionConfiguration.default and this time I get a different error at the end of the download: Task &lt;0457F755-9C52-4CFB-BDB2-F378D0C94912&gt;.&lt;1&gt; failed strict content length check - expected: 0, received: 530692, received (uncompressed): 0 Task &lt;0457F755-9C52-4CFB-BDB2-F378D0C94912&gt;.&lt;1&gt; finished with error [-1005] Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost." UserInfo={NSLocalizedDescription=The network connection was lost., NSErrorFailingURLStringKey=https:/&lt;host&gt;:8190/proxy?Func=downloadVideoByUrl&amp;SessionId=slufzwrMadvyJad8Lkmi9RUNAeqeq, NSErrorFailingURLKey=https://&lt;host&gt;:8190/proxy?Func=downloadVideoByUrl&amp;SessionId=slufzwrMadvyJad8Lkmi9RUNAeqeq, _NSURLErrorRelatedURLSessionTaskErrorKey=( "LocalDownloadTask &lt;0457F755-9C52-4CFB-BDB2-F378D0C94912&gt;.&lt;1&gt;" ), _NSURLErrorFailingURLSessionTaskErrorKey=LocalDownloadTask &lt;0457F755-9C52-4CFB-BDB2-F378D0C94912&gt;.&lt;1&gt;, NSUnderlyingError=0x300d9a7c0 {Error Domain=kCFErrorDomainCFNetwork Code=-1005 "(null)" UserInfo={NSErrorPeerAddressKey=&lt;CFData 0x302139db0 [0x1fcb1f598]&gt;{length = 16, capacity = 16, bytes = 0x10021ffe91e227500000000000000000}}}} The log "failed strict content length check” made me look into the response header, which has the following: content-length: 0 Content-Type: application/force-download Transfer-encoding: chunked Connection: KEEP-ALIVE Content-Transfer-Encoding: binary So it should be fine the way I setup my URLSession. The download works fine in Chrome/Safari/Chrome or Postman. My code used to work a couple of weeks before, so I expect something has changed on the server side, but I can’t find what, and I don’t get much help from the guys on the server side. Has anyone an idea of what’s going on?

This is the log on the publisher side. Publisher discovered the subscriber, but could not pair. Follow up is sent with response rejected

"NSPOSIXErrorDomain Code=65 & iOS18 & Xcode 16". I used 'CocoaAsyncSocket', '~> 7.6.5'. It works fine on 13pro iOS16.4.1 &iphone x 16.7.7， But it's bad on iOS 18.3.

I am trying to intercept localhost connections within NETransparentProxyProvider system extension. As per NENetworkRule documentation If the address is a wildcard address (0.0.0.0 or ::) then the rule will match all destinations except for loopback (127.0.0.1 or ::1). To match loopback traffic set the address to the loopback address. I tried to add NWHostEndpoint *localhostv4 = [NWHostEndpoint endpointWithHostname:@"127.0.0.1" port:@""]; NENetworkRule *localhostv4Rule = [[NENetworkRule alloc] initWithDestinationNetwork:localhostv4 prefix:32 protocol:NENetworkRuleProtocolAny]; in the include network rules. I tried several variations of this rule like port 0, prefix 0 and some others. But the provider disregards the rule and the never receives any traffic going to localhost on any port. Is there any other configuration required to receive localhost traffic in NETransparentProxyProvider?

I have an iPhone app which relies heavily on TCP/IP communication in the local network. Therefore, the application starts a server socket and accepts incoming connections. This worked flawlessly for a long time and we had no problems with this. Problem In the last days however, we observed that for some iPhones with the server role other devices cannot connect to the server of our app. The server does not accept incoming connections on the devices IP address and the client times out. Environment Both iPhones (the server and the client) are in the same network with 192.168.1.0 address range and 255.255.255.0 subnet mask. The server has the IP 192.168.1.11 and the client has 192.168.1.22. This is a normal home WiFi network with no special firewall rules. Both devices have mobile data disabled and the "access local network" permission is granted. The server socket is bound to all interfaces (0.0.0.0). More technical symptoms When the server iPhone is in this faulty state, it seems like it somehow has two ip addresses: 192.168.2.123 and 192.168.1.11 The WiFi preferences show the (correct) .1.11 ip address. The Apps however see the (wrong) .2.123 ip address. I cannot explain where the other ip address comes from and why the device thinks it has this ip address. I've collected interface diagnosis information on a faulty iPhone and it listed the following interfaces and IPs: en0 -> 192.168.2.123 lo0 -> 127.0.0.1 pdp_ip0 (cellular) -> 192.0.0.2 pdp_ip1 to pdp_ip6 (cellular) -> -/- ipsec0 to ipsec6 (vpn) -> -/- llw0 (vpn) -> -/- awdl0 -> -/- anpi0 -> -/- ap1 -> -/- XHC0 -> -/- en1 and en2 (wired) -> -/- utun0 to utun2 (vpn) -> -/- The correct ip of the device is not listed anywhere in this list. A reboot helped to temporarily fix this problem. One user reported the same issue again a few hours later after a reboot. Switching off WiFi and reconnecting does not solve the problem. This issue occurred on several iPhones with the following specs: iOS Version 18.1.1, 18.3.1 iPhone 13 Pro, iPhone 13 Pro Max, iPhone 15 Pro The problem must be on the server side as the client can successfully connect to any other device in the same network. Question(s) Where does this second IP come from and why does the server not accept connections to either ip even though it is bound to 0.0.0.0? Are there any iOS system settings which could lead to this problem? (privacy setting, vpn, ...) What could be done to permanently fix this issue?

Our application currently uses NEFilterPacketProvider to filter network traffic based on Layer 4 rules (5-tuple: source IP, destination IP, source port, destination port, and protocol) on a packet-by-packet basis. We now want to extend this filtering to also consider the associated process—for example, allowing traffic from a specific source IP to a destination IP and port only if it's associated with a specific local process. That is, we’d like to make filtering decisions not just based on the 5-tuple, but also on the identity of the process either sending or receiving the traffic. We’ve looked into NEFilterSocketProvider, which does expose Layer 7 information such as process identifiers. However, it doesn’t seem to be tightly synchronized with the packet flow handled by NEFilterPacketProvider. As a result, there’s a risk that we might only get process information after the TCP handshake is complete, or before the socket is fully bound—at which point some of the 5-tuple fields (such as the local port) may still be unavailable. What we need is a way to correlate the 5-tuple with the relevant process name (either sender or receiver) at the time the first packet—e.g., a SYN packet—is about to be sent or received. Is there a recommended way to achieve this kind of early, process-aware filtering using NetworkExtension APIs?

I am making a USB attached IoT device that follows the Matter approach to connectivity (IP/mDNS/DHCP). I am having conflicts with it as it appears to MacOS as an Ethernet adapter and this is causing it to be assigned as a "default" route, interfering with routing when my Mac is connected to NAT based WiFi. I'd like to be able to hint to MacOS & iPadOS that this is not a routable private network, the subnet should be respected and a default route should not be assigned to it, otherwise the order of the device connection is used by the IP routing tables and I am concerned my non-routable private network will initialize before Wifi and block NAT based internet connectivity. How can I hint to MacOS/iPadOS "this is not a routable private network, this is not a NAT, do not assign me a default route beyond the subnet I have provided you."

I'm writing an application that implements a Bonjour service and browser for the purpose of connecting to Logic Pro and interacting with a MIDI Device Script. Because it's connecting to Logic Pro running on the same system as the application, the service and browser do not need to access anything else on the local network. I'm creating the service and browser with calls like this: err = DNSServiceRegister( &serviceRef, 0, kDNSServiceInterfaceIndexLocalOnly, "MyService", "_osc._udp", "local", nullptr, 52854, txtLen, txtRecord, static_cast<DNSServiceRegisterReply>(myCallback), context ); err = DNSServiceBrowse( &browserRef, 0, kDNSServiceInterfaceIndexLocalOnly, "_osc._udp", nullptr, static_cast<DNSServiceBrowseReply>(browserCallback), context ); Despite the fact that I'm passing in kDNSServiceInterfaceIndexLocalOnly for the network interface, it still triggers an "Allow 'Application' to find devices on local networks?" permissions prompt. How can I avoid that prompt? It is both a significant failure point (in case users don't notice it or click 'Don't Allow' by mistake) but it may also scare them away, since it strongly implies my application is scanning devices on the local network, even though it's doing no such thing!

Hi everyone, I'm developing a visionOS app that allows users to download large video files (similar to a movie download experience, with each file being around 10 GB). I've successfully implemented the core video download functionality using URLSession, and everything works as expected while the app is active. Now, I’m looking to support background downloading. Specifically, I want users to be able to start a download and then leave the app (e.g., switch apps or return to the home screen) while the download continues in the background. Additionally, I’d like to confirm a specific scenario: If the user starts a download, then removes the headset (keeping the device turned on and connected to power), will the download continue in the background? Or does visionOS suspend the app or downloads in this case? I’m considering using a background URLSessionConfiguration (as done in iOS/macOS) to enable this behavior, but I’m not sure if it behaves the same way on visionOS or if there are special limitations or best practices when handling large downloads on this platform. Any insights or official guidance would be greatly appreciated! Thanks!

We have product for network monitoring and we are't able to add support auto-instrumenting the networking requests for URLSession async/wait methods as these methods are't exposed to dynamic environment or not exposed to ObjC and we con't use any of the run-time functionality and we con't override these methods as these methods are't public. looking for a way to add some kind of logic so that when customers use our product they don't have to add any code from there end to monitor this system.

Question: What is the standard, most reliable way to manage temporary files associated with a URLSessionDownloadTask that has been terminated abnormally due to a network error or other issues? Details Hello, I'm currently developing a feature to download multiple files concurrently on iOS using URLSessionDownloadTask, and I have a question regarding the lifecycle of the temporary files created during this process. As I understand it, URLSessionDownloadTask stores incoming data in a temporary file within the tmp directory, typically with a name like CFNetworkDownload_*.tmp. In my testing, temporary files are managed correctly in the normal scenario. For instance, when I call the cancel() method on an active downloadTask and then release all references to it, the corresponding temporary file is automatically cleaned up from the tmp directory shortly after. However, the problem occurs when a download is interrupted abnormally due to external factors, such as a lost network connection. In this situation, the urlSession(_:task:didCompleteWithError:) delegate method is called, but the associated temporary file is not deleted and remains in the tmp directory. I've observed a particularly interesting behavior related to this. Immediately after the error occurs, if I check my app's storage usage in the iOS Settings app, the data size appears to have decreased momentarily. However, the tmp file has not actually been deleted, and after a short while, the storage usage is recalculated to include the size of this orphaned temporary file. Since my app does not support resuming interrupted downloads, these leftover files become orphaned and unnecessarily consume storage. Therefore, I want to ensure they are all reliably deleted. With this context, I'd like to ask the community: What is the standard, most reliable way to manage temporary files associated with a URLSessionDownloadTask that has been terminated abnormally due to a network error or other issues? I am wondering if there is an official guide or a framework-level API to handle these orphaned files. I would appreciate any advice from those with experience in this area. Thank you.

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

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

My code makes an iPhone use the CBCentralManager to talk to devices peripherals over core bluetooth. After attempting a connect to a peripheral device, I get a didConnect callback on CBCentralManagerDelegate. After this I initiate discovery of services using: peripheral.discoverServices([CBUUID(nsuuid: serviceUUID)]) Since I am only interested in discovering my service of interest and not the others to speed up time to the actual sending of data. This also gives me the didDiscoverServices callback without error prints in which I do the following: guard let services = peripheral.services, !services.isEmpty else { print("Empty services") centralManager.cancelPeripheralConnection(peripheral) return } And for next steps if let serviceOfInterest = services.first(where: {$0.uuid == CBUUID(nsuuid: serviceUUID)}) { //double check for service we want initiateDiscoverCharacteristics(peripheral: peripheral, service: serviceOfInterest) } Below is what initiateDiscoverCharacteristics() does. I basically only tries to discover certain characteristics of the selected service: peripheral.discoverCharacteristics( [CBUUID(nsuuid: readUUID), CBUUID(nsuuid: writeUUID)], for: serviceOfInterest) For this also we get the didDiscoverCharacteristicsFor callback without error prints. Here in this callback however we were not doing the serviceOfInterest check to see that we are getting the callback for the service we expect, since our understanding was that we will get didDiscoverCharacteristicsFor callback for the characteristics on the serviceOfInterest because that is what peripheral.discoverCharacteristics() was initiated for. When we go ahead to write some data/subscribe for notify/read data we have 2 guard statements for services and characteristics of a particular service. The first guard below passes: if(peripheral.services == nil) { print("services yet to be discovered \(peripheral.identifier.uuidString)") return } However the second guard below fails: let serviceOfInterest = peripheral.services?.first(where: {$0.uuid == CBUUID(nsuuid: serviceUUID}) if((serviceOfInterest?.characteristics == nil) || (serviceOfInterest?.characteristics == [])) { print("characteristics yet to be discovered \(peripheral.identifier.uuidString)") return } First of all, does the iPhone go ahead and discover other characteristics and services separately even when we explicitly mention the service and the characteristics it should discover? Now if you say yes and that it maybe the reason of our bug because we didn't do a check for serviceOfInterest in didDiscoverCharacteristicsFor callback, then I have another question. Why don't we get a second/third print in didDiscoverCharacteristicsFor callback signifying that more characteristics were discovered? The peripheral device just disconnects after a set timeout (peripheral device used in our testing does this if we are not communicating with it for a certain amount of time). This issue is extremely rare. We have seen it only twice in our customer base. Both the instances were on the same iPhone 15 Pro. Once a few months back and once recently. Currently, this iPhone is having iOS version 18.1.1 running on it.