When filtering traffic to localhost (127.0.0.1), it causes Maven repository synchronization to fail in IntelliJ IDEA. However, Maven works correctly when local traffic is not filtered. I will provide a minimal code reproduction below. - (void)startFilterWithCompletionHandler:(void (^)(NSError *error))completionHandler { // Add code to initialize the filter NSMutableArray *rules = [NSMutableArray array]; NENetworkRule * rule = [[NENetworkRule alloc] initWithRemoteNetwork:nil remotePrefix:0 localNetwork:nil localPrefix:0 protocol:NENetworkRuleProtocolTCP direction:NETrafficDirectionAny]; [rules addObject:[[NEFilterRule alloc]initWithNetworkRule:rule action:NEFilterActionFilterData]]; rule = [[NENetworkRule alloc] initWithRemoteNetwork:nil remotePrefix:0 localNetwork:nil localPrefix:0 protocol:NENetworkRuleProtocolUDP direction:NETrafficDirectionAny]; [rules addObject:[[NEFilterRule alloc]initWithNetworkRule:rule action:NEFilterActionFilterData]]; NWHostEndpoint *hostEndpointIpv4 = [NWHostEndpoint endpointWithHostname:@"127.0.0.1" port:@"0"]; NENetworkRule *localHostRuleIpv4 = [[NENetworkRule alloc] initWithRemoteNetwork:hostEndpointIpv4 remotePrefix:32 localNetwork:hostEndpointIpv4 localPrefix:32 protocol:NENetworkRuleProtocolAny direction:NETrafficDirectionAny]; [rules addObject:[[NEFilterRule alloc]initWithNetworkRule:localHostRuleIpv4 action:NEFilterActionFilterData]]; NEFilterSettings *filterSetting = [[NEFilterSettings alloc] initWithRules:rules defaultAction:NEFilterActionAllow]; [self applySettings:filterSetting completionHandler:^(NSError * _Nullable error) { if (error) { NSLog(@"Failed to apply filter settring: %@", error.localizedDescription); } completionHandler(error); }]; } Maven Sync error: System Log: 默认 17:35:13.184509+0800 kernel cfil_inp_log:6179 <CFIL: outbound TCP data dropped for pre-existing un-filtered flow>: [41046 idea] <TCP out so 3bb6402f58a82e37 - flags 0x800840 0x80> lport 63166 fport 29735 laddr 127.0.0.1 faddr 127.0.0.1 默认 17:35:13.184510+0800 kernel cfil_inp_log:6179 <CFIL: outbound TCP data dropped for pre-existing un-filtered flow>: [41046 idea] <TCP out so d6dde374c8cb613b - flags 0x800840 0x80> lport 63165 fport 29735 laddr 127.0.0.1 faddr 127.0.0.1 默认 17:35:13.529546+0800 kernel cfil_inp_log:6179 <CFIL: outbound TCP data dropped for pre-existing un-filtered flow>: [41046 idea] <TCP out so cc915e74ba29f8cb - flags 0x800840 0x80> lport 63169 fport 39066 laddr 127.0.0.1 faddr 127.0.0.1 默认 17:35:13.529546+0800 kernel cfil_inp_log:6179 <CFIL: outbound TCP data dropped for pre-existing un-filtered flow>: [41046 idea] <TCP out so 2e15c3e54ebcc45 - flags 0x800840 0x80> lport 63168 fport 39066 laddr 127.0.0.1 faddr 127.0.0.1 默认 17:35:14.046094+0800 kernel cfil_inp_log:6179 <CFIL: outbound TCP data dropped for pre-existing un-filtered flow>: [41046 idea] <TCP out so 71f6d3a53472131f - flags 0x800840 0x80> lport 63172 fport 53241 laddr 127.0.0.1 faddr 127.0.0.1 默认 17:35:14.046145+0800 kernel cfil_inp_log:6179 <CFIL: outbound TCP data dropped for pre-existing un-filtered flow>: [41046 idea] <TCP out so c88a367c9717185b - flags 0x800840 0x80> lport 63171 fport 53241 laddr 127.0.0.1 faddr 127.0.0.1 Environment Details: Operating System: macOS 15.5 (Sequoia) IDE: IntelliJ IDEA 2025.1 Relevant Technology: NEFilterDataProvider (Network Extension) I have found reports of similar problems online： https://discussionschinese.apple.com/thread/255270330?sortBy=rank https://blog.csdn.net/weixin_42339552/article/details/137402307 They all seem to be caused by network extension。

Configure the App ID in the Apple Developer Portal. In the Network Extensions section, the Packet Tunnel section is not displayed, as shown in the figure below How to proceed with the configuration of App ID. In the Network Extensions section: Display the Packet Tunnel section Our account is a China region account

Configure the App ID in the Apple Developer Portal. In the Network Extensions section, the Packet Tunnel section is not displayed How to proceed with the configuration of App ID. In the Network Extensions section: Display the Packet Tunnel section Our account is a China region account

I observed the following crash: Code Type: ARM-64 (Native) Parent Process: launchd [1] User ID: 0 Date/Time: 2025-10-07 13:48:29.082 OS Version: macOS 15.6 (24G84) Report Version: 12 Anonymous UUID: 8B651788-4B2E-7869-516B-1DA0D60F3744 Crashed Thread: 3 Dispatch queue: NEFlow queue Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000054 ... Thread 3 Crashed: Dispatch queue: NEFlow queue 0 libdispatch.dylib 0x000000019af6da34 dispatch_async + 192 1 libnetworkextension.dylib 0x00000001b0cf8580 __flow_startup_block_invoke.216 + 124 2 com.apple.NetworkExtension 0x00000001adf97da8 __88-[NEExtensionAppProxyProviderContext setInitialFlowDivertControlSocket:extraValidation:]_block_invoke.90 + 860 3 libnetworkextension.dylib 0x00000001b0cf8140 __flow_startup_block_invoke.214 + 172 4 libdispatch.dylib 0x000000019af67b2c _dispatch_call_block_and_release + 32 5 libdispatch.dylib 0x000000019af8185c _dispatch_client_callout + 16 6 libdispatch.dylib 0x000000019af70350 _dispatch_lane_serial_drain + 740 7 libdispatch.dylib 0x000000019af70e2c _dispatch_lane_invoke + 388 8 libdispatch.dylib 0x000000019af7b264 _dispatch_root_queue_drain_deferred_wlh + 292 9 libdispatch.dylib 0x000000019af7aae8 _dispatch_workloop_worker_thread + 540 10 libsystem_pthread.dylib 0x000000019b11be64 _pthread_wqthread + 292 11 libsystem_pthread.dylib 0x000000019b11ab74 start_wqthread + 8 ... It appears that the crash is caused by the flow director queue becoming NULL when dispatch_async is called (accessing address 0x0000000000000054). Meanwhile, my transparent proxy was still running. I'm wondering if this is a known issue or if anyone else has encountered the same problem. @eskimo

We have a VPN application and we were required by the review team to change the text in the "Add VPN Configuration" dialog due to guideline 5.4.0 Legal: VPN Apps: make it clear to the user what data is being collected and how it will be used in the permission request. It appears that showing that information in the view preceding the VPN configuration adding attempt is no longer enough. However we haven't found any changes in the API allowing to change the text in the mentioned dialog. Is there a technical possibility to change the text in the add VPN configuration dialog? Thank you

There could be a case where-in multiple transparent proxies might exist in the system (for ex., Cisco AnyConnect, GlobalProtect, etc). We want to know if there is a way to order transparent proxies so that the desired transparent proxy gets the request first. During our research, we found a resource which talks about ordering transparent proxies through MDM. https://developer.apple.com/documentation/devicemanagement/vpn/transparentproxy Using this reference, we tried to create a profile and push it through JAMF. Below is the profile that we created and pushed with JAMF. Property List - &lt;?xml version="1.0" encoding="UTF-8"?&gt; &lt;!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"&gt; &lt;plist version="1.0"&gt; &lt;dict&gt; &lt;key&gt;TransparentProxy&lt;/key&gt; &lt;array&gt; &lt;dict&gt; &lt;key&gt;ProviderBundleIdentifier&lt;/key&gt; &lt;string&gt;com.paloaltonetworks.GlobalProtect.client.extension&lt;/string&gt; &lt;key&gt;Order&lt;/key&gt; &lt;string&gt;1&lt;/string&gt; &lt;/dict&gt; &lt;dict&gt; &lt;key&gt;ProviderBundleIdentifier&lt;/key&gt; &lt;string&gt;com.cisco.anyconnect.macos.acsockext&lt;/string&gt; &lt;key&gt;Order&lt;/key&gt; &lt;string&gt;2&lt;/string&gt; &lt;/dict&gt; &lt;dict&gt; &lt;key&gt;ProviderBundleIdentifier&lt;/key&gt; &lt;string&gt;com.mydomain.transparentproxy&lt;/string&gt; &lt;key&gt;Order&lt;/key&gt; &lt;string&gt;3&lt;/string&gt; &lt;/dict&gt; &lt;/array&gt; We are not sure if this is the right way to create the profile, though JAMF is not throwing any error while pushing this profile. We see this profile on the local machine as "/Library/Managed Preferences/com.apple.networking.vpn-transparent-list.plist". Is there a way to know if the profile took effect and the order of transparent proxies has changed. Thanks in advance.

We have an application which is written in Swift, which activates Transparent Proxy network 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 are using JAMF MDM profile for installing our transparent proxy in customer environment. We are using VPN payload(https://developer.apple.com/documentation/devicemanagement/vpn) for this network system extension. This payload does not have any field for order. As per https://developer.apple.com/documentation/devicemanagement/vpn/transparentproxy-data.dictionary documentation there is another payload for TransparentProxy and we could create a Transparent Proxy profile using iMazingProfile Editor. Noticed that, if we add the Order attribute to the VPN/TransparentProxy payload, while installing the extension, the save to preferences fails with "Error in saving TP configuration in updateOnDemandRule permission denied" error. Can we use this Order field to ordering the installed Transparent Proxy extension in a machine? Customer devices will likely have other Transparent Proxy network extensions as well. We want to allow the Customer to control the order in which each Transparent Proxy network extension receives the network traffic. How can we set the order of the Transparent proxy extension that can be deployed using MDM profile with VPN/TransparentProxy payload? Attached the TransparentProxy payload profile for the reference. DGWebProxy_TransparentProxy_iMazing

I've implemented a custom VPN system extension for macOS, utilizing Packet Tunnel Provider. One of the users reported a problem: he was connected to the VPN, and then his Mac entered sleep mode. Upon waking, the VPN is supposed to connect automatically (because of the on-demand rules). The VPN's status changed to 'connecting', but it remained stuck in this status. From my extension logs, I can see that the 'startTunnelWithOption()' function was called 2 minutes after the user clicked the 'connect' button. From the system logs, I noticed some 'suspicious' logs, but I can't be sure if they are related to the problem. Some of them are: kernel: (Sandbox) Sandbox: nesessionmanager(562) deny(1) system-fsctl (_IO "h" 47) entitlement com.apple.developer.endpoint-security.client not present or not true (I don't need this entitlement at the extension) nesessionmanager: [com.apple.networkextension:] NESMVPNSession[Primary Tunnel:XXXXXX(null)]: Skip a start command from YYYYY:session in state connecting NetworkExtension.com.***: RunningBoard doesn't recognize submitted process - treating as a anonymous process sysextd: activateDecision found existing entry of same version: state activated_enabled, ID FAE... Are any of the logs related to the above problem? How can I debug such issues? What info should I get from the user?

I am trying to setup a system-wide DNS-over-TLS for iOS that can be turned off and on from within the app, and I'm struggling with the implementation details. I've searched online, searched forums here, used ChatGPT, and I'm getting conflicting information or code that is simply wrong. I can't find example code that is valid and gets me moving forward. I think I need to use NEDNSProxyProvider via the NetworkExtension. Does that sound correct? I have NetworkExtension -> DNS Proxy Capability set in both the main app and the DNSProxy extension. Also, I want to make sure this is even possible without an MDM. I see conflicting information, some saying this is opened up, but things like https://developer.apple.com/documentation/Technotes/tn3134-network-extension-provider-deployment saying a device needs to be managed. How do private DNS apps do this without MDM? From some responses in the forums it sounds like we need to parse the DNS requests that come in to the handleNewFlow function. Is there good sample code for this parsing? I saw some helpful information from Eskimo (for instance https://developer.apple.com/forums/thread/723831 ) and Matt Eaton ( https://developer.apple.com/forums/thread/665480 )but I'm still confused. So, if I have a DoT URL, is there good sample code somewhere for what startProxy, stopProxy, and handleNewFlow might look like? And valid code to call it from the main app?

Hi, I've encountered a strange behavior in the DNS Proxy Provider extension. Our app implements both DNS Proxy Provider and Content Filter Providers extensions, configured via MDM. When the app is uninstalled, the behavior of the providers differs: For Content Filter Providers (both Filter Control and Filter Data Providers), the providers stop as expected with the stop reason: /** @const NEProviderStopReasonProviderDisabled The provider was disabled. */ case providerDisabled = 5 However, for the DNS Proxy Provider, the provider remains in the "Running" state, even though there is no app available to match the provider's bundle ID in the uploaded configuration profile. When the app is reinstalled: The Content Filter Providers start as expected. The DNS Proxy Provider stops with the stop reason: /** @const NEProviderStopReasonAppUpdate The NEProvider is being updated */ @available(iOS 13.0, *) case appUpdate = 16 At this point, the DNS Proxy Provider remains in an 'Invalid' state. Reinstalling the app a second time seems to resolve the issue, with both the DNS Proxy Provider and Content Filter Providers starting as expected. This issue seems to occur only if some time has passed after the DNS Proxy Provider entered the 'Running' state. It appears as though the system retains a stale configuration for the DNS Proxy Provider, even after the app has been removed. Steps to reproduce: Install the app and configure both DNS Proxy Provider and Content Filter Providers using MDM. Uninstall the app. Content Filter Providers are stopped as expected (NEProviderStopReason.providerDisabled = 5). DNS Proxy Provider remains in the 'Running' state. Reinstall the app. Content Filter Providers start as expected. DNS Proxy Provider stops with NEProviderStopReason.appUpdate (16) and remains 'Invalid'. Reinstall the app again. DNS Proxy Provider now starts as expected. This behavior raises concerns about how the system manages the lifecycle of DNS Proxy Provider, because DNS Proxy Provider is matched with provider bundle id in .mobileconfig file. Has anyone else experienced this issue? Any suggestions on how to address or debug this behavior would be highly appreciated. Thank you!

We're encountering an issue with our Network Extension (utilizing NEPacketTunnelProvider and NETransparentProxy) on macOS 14.5 (23F79). On some systems, the VPN fails to automatically start after a reboot despite calling startVPNTunnel(). There are no error messages. Our code attempts to start the tunnel: ....... do { try manager.connection.startVPNTunnel() Logger.default("Started tunnel successfully") } catch { Logger.error("Failed to launch tunnel") } ...... System log analysis reveals the tunnel stopping due to userLogout (NEProviderStopReason(rawValue: 12)) during reboot. However, the Transparent Proxy stops due to userInitiated (NEProviderStopReason(rawValue: 1)) for the same reboot. We need to understand: Why the VPNTunnel isn't starting automatically. Why the userLogout reason is triggered during reboot. Additional Context: We have manually started the VPN from System Settings before reboot.

Hello, Since the release of iOS 26.0, we are seeing DNS traffic being blocked from within our NEPacketTunnelExtension on some devices. We have not isolated exact reproduction steps, but DNS resolves successfully for a period of time after enabling "iCloud Private Relay" (varying from 1-day to 2-weeks), until it then fails as MDNSResponder then returns: mDNSResponder [Q37046] DetermineUnicastQuerySuppression: Query suppressed for <mask.hash: 'REDACTED'> Addr (blocked by policy) DNS resolution continues to fail for all domains with the above until the device is rebooted. The Packet Tunnel intentionally does not have a DNS server set and this occurs for traffic from the Extension yet off-tunnel, which needs resolution from the system DNS server (and this configuration works perfectly for a period of time before being "blocked by policy"). The following do not resolve the issue once DNS queries are being "blocked by policy" on affected devices: disconnecting then reconnecting the vpn; toggling airplane mode for 10+ seconds; switching connection between WiFi & cellular data; disabling iCloud Private Relay. We have currently only seen this on unmanaged devices running iOS 26.0 or 26.1 beta and with iCloud Private Relay enabled. We did not see this issue on iOS 16,17 nor 18. We also have not yet seen this when iCloud Private Relay is disabled nor on iOS 26.0.1, however we cannot confirm whether they too are also affected. Is there a known a bug with iOS 26.0 & 26.1 Beta 1 that could cause this? How can we prevent DNS requests from NEPacketTunnelExtension being sporadically "blocked by policy" until the device is rebooted? Many thanks in advance.

On one test machine, our extension wouldn't load, because [NETransparentProxyManager loadAllFromPreferencesWithCompletionHandler] can't find a manager, saying Skipping configuration appname because it is of the wrong type. This is the first time I've seen this behaviour. (The containing app tries to find a configuration, if it can't find it it creates one, then modifies whatever it found or created, then stores it. I don't have the right logging yet for that, so I can't see the error messages. [NSLog instead of os_log_error.])

I've been wondering what is the memory limit for network extensions. Specifically, I'm using the NEPacketTunnelProvider extension point.The various posts on this forum mention 5 MB and 6 MB for 32-bit and 64-bit respectively. However I find that (at least on iOS 10) the upper limit seems to be 15 MB. Is this the new memory limit for extensions?

We currently have a PacketTunnelProvider providing a VPN connection to managed devices. Our profile locks this down with OnDemandEnabled and OnDemandUserOverrideDisabled set to true. We've had reports of the OnDemand feature not kicking in on macOS when switching profiles or creating new profiles for managed users (but this works for the initial user login). When switching profiles, OnDemand does not enable; however, if the user manually enables the VPN and then disables, OnDemand will now correctly turn the connection back on. The installed profile contains: OnDemandEnabled: 1 OnDemandRules: Connect Action for WiFi, Cellular, and Ethernet OnDemandUserOverrideDisabled: 1 From sysdiagnose logs, I see some interesting logs for nesessionmanager: Handling a network changed event Resetting VPN On Demand Found 0 registrations for [...].PacketTunnel Failed to find [...].PacketTunnel app extension using neagent Plugin is not available in launch services Plugin is not installed (I also see some failures with LSApplicationProxy, but not sure if those are relevant.) Eventually, I see: Plugin is installed Enabling VPN On Demand And things seem to kick off more as expected from that point on. Do we have any guidance on how to address this issue? We also have a ticket submitted with Feedback Assistant.

How often do we see control filter start and stop? I read somewhere that data filter is long lived and control Filter is short lived. When does the operating system kills the control filter process?

I have been playing around with the new URL Filtering API. I have successfully installed and configured the sample code, Installed the example app to my iPhone, and am also running the PIR server locally on my Mac. In my input.txtpb file, I simply have 2 endpoints: rows: [{ keyword: "instagram.com", value: "1" }, { keyword: "youtube.com/shorts", value: "1" }] Neither of these are blocked when I attempt to load them from either a browser, or their dedicated apps. Are there any debugging tips I should know about? Additionally, I have also noticed a few times I have left the filter running on my phone, after leaving my LAN (where the PIR server is running), suddenly throughout the day I'm having random, completely unrelated endpoints blocked on my phone. I thought this API was never supposed to produce false positives (without calling back to the PIR server for confirmation).

Hi guys, I need to configure a VPN to work only for specific apps. I already have a supervised iPhone, and I’ve successfully configured the VPN, but right now it applies to the whole phone. I need it to work just for some apps. I tried using both Apple Configurator and iMazing, but I can’t find this option there.

We have a customer reporting a bunch of problems with our (Transparent Proxy Provider-based) suite. Looking at a sysdiagnose, I see that our GUI applet was killed: Termination Reason: Namespace PORT_SPACE, Code 14123288431434181290 (Limit 305834 ports) Exceeded system-wide per-process Port Limit Looking at the top.txt file from it, I see that it has 193,086 ports -- compared to about ~250 on one of my test systems. Has anyone run into this? Any idea what might be causing it? (I'm still poring over the sysdiagnose, but I don't see any kernel logs around that time -- except that our process does close a dozen or so ports because of cancellation.)

Hi, I have a VPN product for macOS. When activated, it creates a virtual interface that capture all outgoing traffic for the VPN. the VPN encrypt it, and send it to the tunnel gateway. The gateway then decapsulates the packet and forwards it to the original destination. To achieve this, The vpn modifies the routing table with the following commands: # after packets were encoded with the vpn protocol, re-send them through # the physical interface /sbin/route add -host <tunnel_gateway_address_in_physical_subnet> <default_gateway> -ifp en0 > /dev/null 2>&1 # remove the default rule for en0 and replace it with scoped rule /sbin/route delete default <default_gateway> -ifp en0 > /dev/null 2>&1 /sbin/route add default <default_gateway> -ifscope en0 > /dev/null 2>&1 # create new rule for the virtual interface that will catch all packets # for the vpn /sbin/route add default <tunnel_gateway_address_in_tunnel_subnet> -ifp utunX > /dev/null 2>&1 This works in most cases. However, there are scenarios where the VPN process may crash, stop responding, or another VPN product may alter the routing table. When that happens, packets may no longer go out through the correct interface. Question: Is there a way to reliably reconstruct the routing table from scratch in such scenarios? Ideally, I would like to rebuild the baseline rules for the physical interface (e.g., en0) and then reapply the VPN-specific rules on top. Are there APIs, system utilities, or best practices in macOS for restoring the original routing configuration before reapplying custom VPN routes? Thanks