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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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EAWiFiUnconfiguredAccessoryBrowser "Accessory Setup" UI selects blank/null SSID by default
We've received several reports of a new bug while setting up our products with WAC. The Accessory Setup UI appears with a blank network selected and the message 'This accessory will be set up to join "(null)".' at top. The user can tap "Show Other Networks..." to select another network, but this experience is very confusing. Why does this UI present a choice that is known to be invalid when other valid choices exist? I've captured a screenshot and sysdiagnose from this case. In most cases this problem happens only intermittently, but I can reproduce it consistently by disconnecting my iPhone from any WiFi network (WiFi remains enabled). My suggestion for a better user experience is that this UI should select the default network according to these rules: The network to which iPhone is currently connected. Any network which is in the known/my list for this iPhone Any valid network I believe rule #1 is the existing behavior, but applying rules #2 and #3 as fallbacks would be an improvement. Is there anything I can change in my iOS code or in my accessory's WAC server to improve this experience?
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192
Sep ’25
ios26 beta5 VPN Profile not installing
I have a custom VPN app that uses NETunnelProviderManager to install a VPN Profile if one is not already installed. On previous iOS versions this would open the VPN Settings and ask for either the PIN, FaceID or TouchID and install the profile. With iOS 26 beta5 it opens the VPN Settings and stops. Is this a bug in iOS 26? Have there been changes to NETunnelProviderManager for iOS 26 that I'm not aware of? FYI we do the samething on macOS 26 beta5 and that works as expected.
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623
Aug ’25
Wi-Fi Aware between iOS 26 and Android device
Eager to see the Wi-Fi Aware communication between iPhone (iOS 26) and an Android device, I tried iOS 26 beta on my iPhone16. and tried below code snippet from provided example at https://developer.apple.com/documentation/wifiaware/building-peer-to-peer-apps. Idea is to first verify discovery of Android WiFiAware service on iOS. extension WAPublishableService { public static var simulationService: WAPublishableService { allServices[simulationServiceName]! } } extension WASubscribableService { public static var simulationService: WASubscribableService { allServices[simulationServiceName]! } } struct ContentView: View { @State private var showingDevicePicker = false @State private var pairedDevices: [WAPairedDevice] = [] // To hold discovered/paired devices var body: some View { VStack { Button("Discover Devices") { showingDevicePicker = true // Trigger the device picker presentation } .sheet(isPresented: $showingDevicePicker) { DevicePicker(.wifiAware(.connecting(to: .selected([]), from: .simulationService))) { endpoint in print("Paired Endpoint: \(endpoint)") } label: { Image(systemName: "plus") Text("Add Device") } fallback: { Image(systemName: "xmark.circle") Text("Unavailable") } } List(pairedDevices) { device in Text(device.name ?? "Unknown Device") } } } } With suggested entitlement of WiFiAware and info.plist of service info. Then I had Android device with WIFiAware service publishing service (service name set '_sat-simulation._udp') from this app https://github.com/anagramrice/NAN. But above iOS app is unable to find the service published from android device. Am I missing something? Note: the above Android-NAN app seems to be working fine between Android to Another Android.
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1.5k
Sep ’25
URLCache behavior for request with different header values
Greetings, I would like to understand this URLCache behavior for two different requests to the same end point but with a different header value. Here is a code with comment explaining the behavior. // Create a request to for a url. let url = URL(string: "https://<my url>?f=json")! var request = URLRequest(url: url) // Set custom header with a value. request.setValue("myvalue", forHTTPHeaderField: "CustomField") // Send request to get the response. let (data, response) = try await URLSession.shared.data(for: request) print("data: \(String(describing: String(data: data, encoding: .utf8)))") print("response: \(response)") // Create second request to the same url but with different value of custom header field. var request2 = URLRequest(url: url) request2.setValue("newvalue", forHTTPHeaderField: "CustomField") // Check the URL cache for second request and it returns the response // of the first request even though the second request has different header value. let cachedResponse = URLCache.shared.cachedResponse(for: request2) print("cachedResponse: \(cachedResponse?.response)") Is this a bug in URLCache that request headers are not matched while returning the response? Is this an expected behavior? If yes, why?
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1.6k
Aug ’25
Local network access disabled after macOS restart
My application needs local network access. When it is started for the first time, the user gets a prompt to enable local network access (as expected). The application is then shown as enabled in Privacy & Security / Local Network and local network access is working. If macOS is then shutdown and restarted, local network access is blocked for the application even though it is still shown as enabled in Privacy & Security / Local Network. Local network access can be restored either by toggling permission off and on in Privacy & Security / Local Network or by disabling and enabling Wi-Fi. This behaviour is consistent on Sequoia 15.1. It happens sometimes on 15.0 and 15.0.1 but not every time. Is my application doing something wrong or is this a Sequoia issue? If it is a Sequoia issue, is there some change I can make to my application to work around it?
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3.1k
Jul ’25
Wi-Fi Aware Sample doesn't build in Xcode 26.0 beta
Hello, I'm trying to build the sample app from Building peer-to-peer apps that demonstrates Wi-Fi Aware. Upon downloading the example source code, opening it in Xcode 26.0 beta, and building the app, the compiler fails with: DeviceDiscoveryPairingView.swift:8:8 No such module 'DeviceDiscoveryUI' Is this a known issue? I know that DeviceDiscoveryUI was previously only a tvOS capability. Thanks
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136
Jun ’25
macOS Tahoe: IPMonitor incorrectly re-ranks interfaces causing VPN DNS leaks
Description Enterprise users are experiencing VPN resource access failures after upgrading to macOS Tahoe. Investigation indicates that configd (specifically IPMonitor) is incorrectly re-ranking network interfaces after a connectivity failure with probe server. This results in DNS queries routing through the physical network adapter (en0) instead of the VPN virtual adapter, even while the tunnel is active. This behaviour is not seen in previous macOS versions. Steps to Reproduce: Connect to an enterprise VPN (e.g., Ivanti Secure Access). Trigger a transient network condition where the Apple probe server is unreachable. For example make the DNS server down for 30 sec. Observe the system routing DNS queries for internal resources to the physical adapter. Expected Results The: VPN virtual interface should maintain its primary rank for enterprise DNS queries regardless of the physical adapter's probe status. Actual Results: IPMonitor detects an UplinkIssue, deprioritizes the VPN interface, and elevates the physical adapter to a higher priority rank. Technical Root Cause & Logs: The system logs show IPMonitor identifying an issue and modifying the interface priority at 16:03:54: IPMonitor Detection: The process identifies an inability to reach the Apple probe server and marks en0 with an advisory: Log snippet 2026-01-06 16:03:53.956399+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] configd[594] SetInterfaceAdvisory(en0) = UplinkIssue (2) reason='unable to reach probe server' Interface Re-ranking: Immediately following, IPMonitor recalculates the rank, placing the physical service ID at a higher priority (lower numerical rank) than the VPN service ID (net.pulsesecure...): Log snippet 2026-01-06 16:03:53.967935+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] 0. en0 serviceID=50CD9266-B097-4664-BFE6-7BAFCC5E9DC0 addr=192.168.0.128 rank=0x200000d 2026-01-06 16:03:53.967947+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] 1. en0 serviceID=net.pulsesecure.pulse.nc.main addr=192.168.0.128 rank=0x2ffffff 3.Physical adapter Is selected as Primary Interface: 2026-01-06 16:03:53.968145+0100 localhost configd[594]: [com.apple.SystemConfiguration:IPMonitor] 50CD9266-B097-4664-BFE6-7BAFCC5E9DC0 is the new primary IPv4 configd[594]: 50CD9266-B097-4664-BFE6-7BAFCC5E9DC0 is the new primary DNS Packet Trace Evidence Wireshark confirms that DNS queries for enterprise-specific DNS servers are being originated from the physical IP (192.168.0.128) instead of the virtual adapter: Time: 16:03:54.084 Source: 192.168.0.128 (Physical Adapter) Destination: 172.29.155.115 (Internal VPN DNS Server) Result: Connectivity Failure (Queries sent outside the tunnel)
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2d
How to avoid my local server flows in Transparent App Proxy
I have written the Transparent App Proxy and can capture the network flow and send it to my local server. I want to avoid any processing on the traffic outgoing from my server and establish a connection with a remote server, but instead of connecting to the remote server, it again gets captured and sent back to my local server. I am not getting any clue on how to ignore these flows originating from my server. Any pointers, API, or mechanisms that will help me?
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263
Apr ’25
Is it possible to scan for nearby WiFi networks and connect to a device in AP mode on iOS?
In our iOS application, we need to list available WiFi networks so that users can select one for device configuration. Here's the workflow: Initially, the hardware device acts as a WiFi Access Point (AP). The app should scan for nearby WiFi networks to detect the device's AP. The app connects temporarily to this AP and sends the selected WiFi credentials to the device. The device then connects to the selected WiFi network and stops broadcasting its AP. Is this flow achievable on iOS? We understand that Apple restricts access to WiFi scanning APIs — are there any supported methods (e.g., using NEHotspotHelper) or entitlements (such as MFi) that could enable this?
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141
Jun ’25
Network Push Provider Wifi Selection Behavior
In our App, we have a network extension with a NEAppPushProvider subclass running. We run the following steps Setup a dual-band wireless router per the following: Broadcasting 2.4 GHz and 5 GHz channels Same SSID names for both channels Connected to the production network to the router DHCP assigning addresses in the 10.1.x.x network Connect the mobile device to the 5 GHz network (if needed, turn off the 2.4 GHz network temporarily; once the device connects to the 5 GHz network, the 2.4 GHz network can be turned back on). Create a NEAppPushManager in the App, using the SSID from the above mentioned network and set it to the matchSSIDs property. Call saveToPreferences() on the push manager to save. A. We have UI that shows the extension has been started and it has connected to the server successfully. Walk out of the range of the 5 GHz channel of the router, but stay within range of the 2.4ghz channel. Wait for the mobile device to connect to the 2.4 GHz channel. Expected: The extension would reconnect to the 2.4ghz network. Observed: The extension does not reconnect. Checking the logs for the extension we see that the following was called in the push provider subclass. stop(with:completionHandler:) > PID: 808 | 🗒️🛑 Stopped with reason 3: "noNetworkAvailable" The expectation is that start() on the NEAppPushProvider subclass would be called. Is this an incorrect expectation? How does the NEAppPushProvider handle same network SSID roaming among various band frequencies? I looked at the documentation and did not find any settings targeting 2.4 or 5 ghz networks. Please advise on what to do.
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136
Apr ’25
NEURLFilterManager Error 2 in macOS - How to Validate Configuration Parameters for setConfiguration or saveToPreferences
I'm currently testing URLFilter for use in a macOS product. After calling loadFromPreferences, I set the following configuration parameters: pirServerURL = URL(string: "http://localhost:8080")! pirAuthenticationToken = "AAAA" controlProviderBundleIdentifier = "{extension app bundle identifier}" However, when I call saveToPreferences, I get an Invalid Configuration error. Is there a way to determine which parameter is invalid or incorrectly set? Also, I would appreciate any macOS-specific examples of using NEURLFilterManager, as most of the documentation I’ve found seems to focus on iOS. Thank you.
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74
Nov ’25
On-demand rules
I've implemented a custom system extension VPN for macOS using Packet Tunnel Provider. The VPN is configured with on-demand, and a rule to always connect whenever there's traffic: onDemandRules = [NEOnDemandRuleConnect()] As expected, if the VPN isn't active, all traffic gets blocked until it is ready. Not expected: In the following scenario, there is some 'traffic leak': Use only WiFi (not wired cable) Connect the VPN Disable the WiFi and wait for the VPN to disconnect Enable the WiFi Some packets are routed outside the VPN, and aren't being blocked Some moments after, all traffic will be blocked, and the VPN will start the 'connecting' process. Is the above scenario a 'known' issue? Can it be a race condition in the OS, where some packets can be sent after the network is brought back before the VPN process starts? Is there any way to fix this problem? P.S: I'm not using flags such as 'capture all network'
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144
Apr ’25
Issue Sending Multicast Packets Across Multiple Interfaces Using NWConnectionGroup
Hi everyone, I'm currently working on a project where I need to send multicast packets across all available network interfaces using Apple Network Framework's NWConnectionGroup. Specifically, the MacBook (device I am using for sending multicast requests, MacOS: 15.1) is connected to two networks: Wi-Fi (Network 1) and Ethernet (Network 2), and I need to send multicast requests over both interfaces. I tried using the .requiredInterface property as suggested by Eskimo in this post, but I’m running into issues. It seems like I can't create an NWInterface object because it doesn't have any initializers. Here is the code which I wrote: var multicast_group_descriptor : NWMulticastGroup var multicast_endpoint : NWEndpoint multicast_endpoint = NWEndpoint.hostPort(host: NWEndpoint.Host("234.0.0.1"), port: NWEndpoint.Port(rawValue: 49154)!) var connection_group : NWConnectionGroup var multicast_params : NWParameters multicast_params = NWParameters.udp var interface = NWInterface(NWInterface.InterfaceType.wiredEthernet) I get following error: 'NWInterface' cannot be constructed because it has no accessible initializers I also experimented with the .requiredInterfaceType property. Even when I set it to .wiredEthernet and then change it to .wifi, I am still unable to send requests over the Wi-Fi network. Here is the code I wrote: var multicast_params : NWParameters multicast_params = NWParameters.udp multicast_params.allowLocalEndpointReuse = true multicast_params.requiredInterfaceType = .wiredEthernet var ip = multicast_params.defaultProtocolStack.internetProtocol! as! NWProtocolIP.Options ip.disableMulticastLoopback = true connection_group = NWConnectionGroup(with: multicast_group_descriptor, using: multicast_params) connection_group.stateUpdateHandler = { state in print(state) if state == .ready { connection_group.send(content: "Hello from machine on 15".data(using: .utf8)) { error in print("Send to mg1 completed on wired Ethernet with error \(error?.errorCode)") var params = connection_group.parameters params.requiredInterfaceType = .wifi connection_group.send(content: "Hello from machine on 15 P2 on Wi-Fi".data(using: .utf8)) { error in print("Send to mg1 completed on Wi-Fi with error \(error?.errorCode)") } } } } Is this expected behavior when using NWConnectionGroup? Or is there a different approach I should take to ensure multicast requests are sent over both interfaces simultaneously? Any insights or suggestions would be greatly appreciated! Thanks in advance, Harshal
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615
Mar ’25
The network connection fails with NEFilterDataProvider and QQMusic running at the same time
The environment: macOS 12.0 ~ 15.6 A NetworkExtension NEFilterDataProvider configured with filterSockets = YES, filterPackets = NO, and it doesn't actually block any network connection. QQMusic (download: https://y.qq.com/n/ryqq/download_detail/mac?ADTAG=YQQ) is constantly playing. Any of the following operations can reproduce the issue: Kill the NetworkExtension process and then restarted by the system. Disable the NEFilterDataProvider, and then enable it. When this problem occurs, there are two different phenomena on the NetworkExtension process: It is zombie, or is in high CPU state (100%). When the NetworkExtension process is zombie, obviously, the new network connections will enter it, and they can't be disposed by the old zombie process, so the network is disconnected. Spindump-qqmusic-ne-zombie When the NetworkExtension process is in high CPU state, its thread DispatchQueue "NEFilterExtensionProviderContext queue" is blocked in the kernel when calling close. Spindump-qqmusic-ne-cpuhigh In most cases, the network will recover after stopping QQ Music, that is the suspended zombie NetworkExtension process will exist or the cpu of it return to normal. To reproduce the issue in a simple environment, I have tried many ways to simulate the network behavior of QQMusic, but all failed. It seems that this issue is caused by UDP traffic of QQMusic, because everything is ok after blocking the UDP connections of QQMusic (the music is still playing at this time) in the NEFilterDataProvider.
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142
Oct ’25
SSL certificate failure
This problem doesn’t appear to relate to the app as everything worked when using http (although an https setup issue may still be the problem). The problem appears to relate to the SSL server certificate on the Ubuntu server and the fact that apple does not accept that it is secure. However I have no problem with the equivalent Android app or web browser connections to the same rest API web services. There are numerous posts on these problems on Apple and other Forums, but none have helped me successfully address the issue. I ran an SSL server test on https://www.ssllabs.com/ssltest/ which gives ratings for SSL sites. The test gave an A rating although a number of minor issues were shown that may be crucial to the iOS failure. Some Sectigo certificates said self signed, which I couldn't understand. Error message from XCode log attached 2025-09-10 10:28:01.725091+0100 locateandclock[2291:1585213] ATS failed system trust 2025-09-10 10:28:01.725192+0100 locateandclock[2291:1585213] Connection 1: system TLS Trust evaluation failed(-9802) 2025-09-10 10:28:01.725291+0100 locateandclock[2291:1585213] Connection 1: TLS Trust encountered error 3:-9802 2025-09-10 10:28:01.725352+0100 locateandclock[2291:1585213] Connection 1: encountered error(3:-9802) 2025-09-10 10:28:01.726727+0100 locateandclock[2291:1585213] Task <4E41098F-6B71-4FB8-8753-78DD32961812>.<1> HTTP load failed, 0/0 bytes (error code: -1200 [3:-9802]) 2025-09-10 10:28:01.736504+0100 locateandclock[2291:1585213] Task <4E41098F-6B71-4FB8-8753-78DD32961812>.<1> finished with error [-1200] Error Domain=NSURLErrorDomain Code=-1200 "An SSL error has occurred and a secure connection to the server cannot be made." UserInfo={NSLocalizedRecoverySuggestion=Would you like to connect to the server anyway?, _kCFStreamErrorDomainKey=3, NSErrorPeerCertificateChainKey=( "<cert(0x10681be00) s: *.xxxxxxxxxxx.co.uk i: Sectigo Public Server Authentication CA DV R36>", "<cert(0x10681c800) s: Sectigo Public Server Authentication CA DV R36 i: Sectigo Public Server Authentication Root R46>", "<cert(0x10681d200) s: Sectigo Public Server Authentication Root R46 i: Sectigo Public Server Authentication Root R46>" ), NSErrorClientCertificateStateKey=0, NSErrorFailingURLKey=https://xxxxxxxxxxxx.co.uk/insertclocking, NSErrorFailingURLStringKey=https://xxxxxxxxxxxx.co.uk/insertclocking, NSUnderlyingError=0x282361650 {Error Domain=kCFErrorDomainCFNetwork Code=-1200 "(null)" UserInfo={_kCFStreamPropertySSLClientCertificateState=0, kCFStreamPropertySSLPeerTrust=<SecTrustRef: 0x281cf4460>, _kCFNetworkCFStreamSSLErrorOriginalValue=-9802, _kCFStreamErrorDomainKey=3, _kCFStreamErrorCodeKey=-9802, kCFStreamPropertySSLPeerCertificates=( "<cert(0x10681be00) s: *.xxxxxxxxxxxxxco.uk i: Sectigo Public Server Authentication CA DV R36>", "<cert(0x10681c800) s: Sectigo Public Server Authentication CA DV R36 i: Sectigo Public Server Authentication Root R46>", "<cert(0x10681d200) s: Sectigo Public Server Authentication Root R46 i: Sectigo Public Server Authentication Root R46>" )}}, _NSURLErrorRelatedURLSessionTaskErrorKey=( "LocalDataTask <4E41098F-6B71-4FB8-8753-78DD32961812>.<1>" ), _kCFStreamErrorCodeKey=-9802, _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <4E41098F-6B71-4FB8-8753-78DD32961812>.<1>, NSURLErrorFailingURLPeerTrustErrorKey=<SecTrustRef: 0x281cf4460>, NSLocalizedDescription=An SSL error has occurred and a secure connection to the server cannot be made.}
5
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265
Oct ’25
Failed to enable the Network Extension
In my application, there is a Network Extension with the bundle ID com.xxx.agent.yyy.zzz.ne. There is a user upgraded their system to macOS Sequoia 15.3, they faced an issue where enabling this Network Extension failed. Even after uninstalling the application and the Network Extension, restarting the system, and reinstalling multiple times, the enabling process still failed. it alert: Failed to enable the Network Extension. When checking the status via "systemextension list", it always shows "activated waiting for user". This shows the normal enabling process log: This shows the log when the enabling fails upon clicking. Strangely enough, there is no activation operation log when it fails. What could be the problem?
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706
Feb ’25
Local network access is blocked when two almost identical apps are installed
We are developing an enterprise app that connects to a local server. It uses simple URLSessions. There is a view in the app where you enter the server url (IP address) and a connection check is made. iOS asks for permission to access the local network. Everything works. If the server is reachable, the connection info is saved. Recently we encountered a very strange issue: We also have a beta version of this app. If we first install the normal version on a device, enter the server IP, save, and then install the beta version and do the same there: It does not get a connection (it waits for the timeout). The strange part is: If I try to configure the connection in the normal version again, it also does not work, it just waits for the timeout. The really strange part: When I delete the beta version, while the normal version is waiting for its connection, the connection succeeds immediately. Both versions have a different display name, bundle id. I also tried using a device that is not in our MDM: same problem. Even the iOS version seems to have no impact: I tried on iOS 15, 18 and 26. Is there an explanation and hopefully also a solution to this problem?
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54
Dec ’25
How to find WHY my app triggers LNP popoup on MacOS 15
My App is a rather small menu-bar status-item app with 2 informational windows. It does NOT make use of ANY of the APIs mentioned here: https://developer.apple.com/forums/thread/663874 that are bound to need "Local Network" hence trigger TCC dialog. Yet - on first run of the app, the dialog pops. App is Obj-C, and the only APIs used are Notification-Center (for scheduling local notifications to the user), XPC connections and calls to other (our) apps for gathering that information, plus normal AppKit windowing (Controls, Text-fields, etc.) nothing else. Obviously SOMETHING I do causes the thing - and I know for sure this app DOES NOT NEED access to the local network - only I do not know how to identify the specific API I need to avoid using (or change the way I'm using) Are there any specific system logs to watch for? Is there any official set of APIs that will trigger the dialog? Provided that I cannot avoid this - could this permission be granted via MDM profile payload? Our product comes with
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1k
Jan ’25