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 TCP and UDP ports used by Apple software products support article 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. WWDC 2025 Session 250 Use structured concurrency with Network framework — This is a great introduction to the new Network framework API introduced in appleOS 2026. 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 Wi-Fi (general): How to modernize your captive network developer news post Wi-Fi Fundamentals forums post Filing a Wi-Fi Bug Report forums post Working with a Wi-Fi Accessory forums post — This is part of the Extra-ordinary Networking series. Wi-Fi (iOS): TN3111 iOS Wi-Fi API overview technote Wi-Fi Aware framework documentation Building peer-to-peer apps sample code WirelessInsights framework documentation iOS Network Signal Strength forums post Network Extension Resources Wi-Fi on macOS: Forums tag: Core WLAN Core WLAN framework documentation 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. WWDC 2025 Session 314 Get ahead with quantum-secure cryptography 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. Prepare your network environment for stricter security requirements support article — This is primarily of interest to folks developing management software, for example, an MDM server. 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 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.

I'm trying to write a NWProtocolFramerImplementation class that will be channeled through a Framer wrapper. There are still some parts I need figuring out. For handleOutput(framer: message: messageLength: isComplete), what do the last two parameters do? Does isComplete refer to the end of the current conversation, or the entire connection? Why would we submit a messageLength if the data size should already be implied within message? If I parse by line breaks, is there a way to indicate if the latest line is the last of the current conversation, either input or output?

Hi all, we are building a custom controller for ATDECC, which is a layer 2 protocol standardized by IEEE in 1722.1. Our controller can work on multiple network interfaces at the same time . It uses the interface's MAC address to identify, on which interface a certain AVB / ATDECC device was discovered. It then sends replies for this device only to this interface. This controller worked fine up to and including macOS 26, but when running the same code on macOS 27, we cannot get the MAC addresses for the local interfaces anymore, but we receive 02:00:00:00:00:00 for each of them. This seems to indicate that the MAC address was redacted (looks like the same MAC address, that is being returned since iOS 11 due to privacy reason). Is this a bug or is macOS going to redact the MAC addresses also in the final release? If MAC addresses are being redacted, would it help to request access to the new entitlement called com.apple.developer.networking.topology-observation? I attached a little code snippet, that returns actual MAC addresses on macOS 26, but redacted ones on macOS 27. Build with clang++ -std=c++23 -o ifprobe ifprobe.cpp and then run it with ./ifprobe. ifprobe.cpp

For important background information, read Extra-ordinary Networking before reading this. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" Network Interface APIs Most developers don’t need to interact directly with network interfaces. If you do, read this post for a summary of the APIs available to you. Before you read this, read Network Interface Concepts. Interface List The standard way to get a list of interfaces and their addresses is getifaddrs. To learn more about this API, see its man page. A network interface has four fundamental attributes: A set of flags — These are packed into a CUnsignedInt. The flags bits are declared in <net/if.h>, starting with IFF_UP. An interface type — See Network Interface Type, below. An interface index — Valid indexes are greater than 0. A BSD interface name. For example, an Ethernet interface might be called en0. The interface name is shared between multiple network interfaces running over a given hardware interface. For example, IPv4 and IPv6 running over that Ethernet interface will both have the name en0. WARNING BSD interface names are not considered API. There’s no guarantee, for example, that an iPhone’s Wi-Fi interface is en0. You can map between the last two using if_indextoname and if_nametoindex. See the if_indextoname man page for details. An interface may also have address information. If present, this always includes the interface address (ifa_addr) and the network mask (ifa_netmask). In addition: Broadcast-capable interfaces (IFF_BROADCAST) have a broadcast address (ifa_broadaddr, which is an alias for ifa_dstaddr). Point-to-point interfaces (IFF_POINTOPOINT) have a destination address (ifa_dstaddr). Calling getifaddrs from Swift is a bit tricky. For an example of this, see QSocket: Interfaces. IP Address List Once you have getifaddrs working, it’s relatively easy to manipulate the results to build a list of just IP addresses, a list of IP addresses for each interface, and so on. QSocket: Interfaces has some Swift snippets that show this. Interface List Updates The interface list can change over time. Hardware interfaces can be added and removed, network interfaces come up and go down, and their addresses can change. It’s best to avoid caching information from getifaddrs. If thats unavoidable, use the kNotifySCNetworkChange Darwin notification to update your cache. For information about registering for Darwin notifications, see the notify man page (in section 3). This notification just tells you that something has changed. It’s up to you to fetch the new interface list and adjust your cache accordingly. You’ll find that this notification is sometimes posted numerous times in rapid succession. To avoid unnecessary thrashing, debounce it. While the Darwin notification API is easy to call from Swift, Swift does not import kNotifySCNetworkChange. To fix that, define that value yourself, calling a C function to get the value: var kNotifySCNetworkChange: UnsafePointer<CChar> { networkChangeNotifyKey() } Here’s what that C function looks like: extern const char * networkChangeNotifyKey(void) { return kNotifySCNetworkChange; } Network Interface Type There are two ways to think about a network interface’s type. Historically there were a wide variety of weird and wonderful types of network interfaces. The following code gets this legacy value for a specific BSD interface name: func legacyTypeForInterfaceNamed(_ name: String) -> UInt8? { var addrList: UnsafeMutablePointer<ifaddrs>? = nil let err = getifaddrs(&addrList) // In theory we could check `errno` here but, honestly, what are gonna // do with that info? guard err >= 0, let first = addrList else { return nil } defer { freeifaddrs(addrList) } return sequence(first: first, next: { $0.pointee.ifa_next }) .compactMap { addr in guard let nameC = addr.pointee.ifa_name, name == String(cString: nameC), let sa = addr.pointee.ifa_addr, sa.pointee.sa_family == AF_LINK, let data = addr.pointee.ifa_data else { return nil } return data.assumingMemoryBound(to: if_data.self).pointee.ifi_type } .first } The values are defined in <net/if_types.h>, starting with IFT_OTHER. However, this value is rarely useful because many interfaces ‘look like’ Ethernet and thus have a type of IFT_ETHER. Network framework has the concept of an interface’s functional type. This is an indication of how the interface fits into the system. There are two ways to get an interface’s functional type: If you’re using Network framework and have an NWInterface value, get the type property. If not, call ioctl with a SIOCGIFFUNCTIONALTYPE request. The return values are defined in <net/if.h>, starting with IFRTYPE_FUNCTIONAL_UNKNOWN. Swift does not import SIOCGIFFUNCTIONALTYPE, so it’s best to write this code in a C: extern uint32_t functionalTypeForInterfaceNamed(const char * name) { int fd = socket(AF_INET, SOCK_DGRAM, 0); if (fd < 0) { return IFRTYPE_FUNCTIONAL_UNKNOWN; } struct ifreq ifr = {}; strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name)); bool success = ioctl(fd, SIOCGIFFUNCTIONALTYPE, &ifr) >= 0; int junk = close(fd); assert(junk == 0); if ( ! success ) { return IFRTYPE_FUNCTIONAL_UNKNOWN; } return ifr.ifr_ifru.ifru_functional_type; } Finally, TN3158 Resolving Xcode 15 device connection issues documents the SIOCGIFDIRECTLINK flag as a specific way to identify the network interfaces uses by Xcode for device connection traffic. Routing Sockets macOS supports the traditional BSD routine socket interface. See the route man page for details. Note You can access some routing socket functionality via sysctl, and all of this section applies to that as well. Other Apple platforms don’t support routing sockets [1]. On macOS it’s reasonable to use a routing socket to learn about the current state of the networking stack and be notified of changes to that state. Doing this on macOS 27 and later may require you to sign your code with the com.apple.developer.networking.topology-observation entitlement. In Xcode, add the Network Topology Observation capability [2] to your target. This is a restricted entitlement, which means it must be authorised by a provisioning profile. If you’re building a command-line tool, follow the advice in Signing a daemon with a restricted entitlement. Don’t use a routing socket to change the state of the networking stack. Such activities are not supported because macOS maintains its source of truth outside of the kernel, primarily in the System Configuration infrastructure [3]. If you make changes behind the back of this infrastructure then, in the best case, they’ll simply be overwritten at some point in the future, but in the worst case you could trigger stability problems. [1] You may or may not be able to open one, based on the current sandbox setup. Even if you can, that effort is not supported because the declarations required to use the socket, most obviously rt_msghdr, are only present in the macOS SDK. And no, copying declarations from one SDK to another is not supported (-; [2] There’s no link to the docs for this capability because that hasn’t yet landed (r. 181611259). [3] See System Configuration Programming Guidelines for a general introduction this architecture. Revision History 2026-09-23 Added the Routing Sockets section. 2025-12-10 Added info about SIOCGIFDIRECTLINK. 2023-07-19 First posted.

I am developing a consumer iOS app for App Store distribution and would like to confirm the appropriate public API for the following use case. The app needs to measure the amount of network traffic passing through the device over short time intervals, for example once per second or more frequently. The app does not need to inspect packet contents, block or filter traffic, or provide a remote VPN service. It also should not generate dedicated network traffic solely for speed measurement. The goal is only to observe device-wide network traffic volume and convert that information into a simple real-time indicator for the user. I am currently investigating the Network Extension framework. Would NEPacketTunnelProvider be an appropriate API for this use case? If not, is there another supported Network Extension provider or other public iOS API intended for measuring device-wide network traffic in this manner? I would like to choose an architecture that is technically supported by Apple and appropriate for a consumer app distributed through the App Store before beginning implementation.

I'm developing a macOS security tool using NEFilterDataProvider as a system extension. On macOS 26 beta (25E241), sysextd consistently rejects my extension with: sysextd: no policy, cannot allow apps outside /Applications Configuration: App installed in /Applications/ Signed with Developer ID Application (693DSH8GN5) Entitlement: com.apple.developer.networking.networkextension = content-filter-provider com.apple.developer.system-extension.install = true Developer Mode enabled on test machine Comparison with Little Snitch: Little Snitch runs correctly on the same machine. Key differences I found: Little Snitch uses content-filter-provider-systemextension instead of content-filter-provider Little Snitch has com.apple.security.app-sandbox = false Both signed with Developer ID Application When I switch to content-filter-provider-systemextension, Xcode rejects every provisioning profile because none match that entitlement value, and the Developer Portal doesn't expose fine-grained control over the Network Extensions array values. Questions Is content-filter-provider-systemextension the correct entitlement for system extensions on macOS 26? How should the provisioning profile be configured to support it? Is there a known sysextd issue on macOS 26 beta causing this regardless of configuration? Is there - somewhere! - a guide on how to build such an extension? Thanks in advance for your help.

I am testing NEURLFilter on macOS using the SimpleURLFilter sample, and I am seeing a failure from neagent while it is saving the local URL prefilter Bloom filter to its mmap file. The relevant log is: neagent +[NEBloomFilter mmapToFile:data:dataLength:numberOfBits:numberOfHashes:murmurSeed:tag:]: NEBloomFilter - failed to open mmap file /private/var/db/urlPrefilter/com.apple.networkextension.url-prefilter-data.temp.com.example.apple-samplecode.SimpleURLFilterTC3Q7MAJXF <errno 13 - Permission denied> neagent <NEAgentURLFilterExtension: 0xc8ce64280>: -[NEAgentURLFilterExtension startURLFilter]_block_invoke - Failed to save first fetch of pre-filter data Environment: macOS: 26.5.1 (25F80) Xcode: 26.5 (17F42) Platform: macOS Signing type: Apple Development (automatically manage signing) What I am doing: Build and run the containing app. Save and enable the NEURLFilterManager configuration. The URL filter provider starts. The provider's prefilter code is reached. neagent logs the mmap failure above while trying to open a temporary file under /private/var/db/urlPrefilter. Expected result: neagent should be able to create or open its system-managed URL prefilter cache / mmap file under /private/var/db/urlPrefilter, and the local Bloom filter should be loaded successfully. Actual result: neagent fails to open the temporary mmap file with errno 13 Permission denied: /private/var/db/urlPrefilter/com.apple.networkextension.url-prefilter-data.temp.<bundle/team-specific suffix> I am not manually creating, modifying, or chmod/chown-ing /private/var/db/urlPrefilter or anything inside it. The directory and its contents are entirely system-managed. The failure appears to happen inside neagent while it is handling the system-managed URL prefilter cache. The failure occurs at the mmapToFile: step while neagent saves the Bloom filter prefilter data. Directory state: drwxr-xr-x 2 root wheel 64 /private/var/db/urlPrefilter Has anyone else encountered this? Any suggestions on what could cause neagent to fail with errno 13 on its own mmap file under /private/var/db/urlPrefilter?

Hello, Feedback Assistant report: FB24876147. I develop a Unity-based iOS app. Some customers in mainland China report losing Internet access after an app update, while most installations continue working. We have received similar reports since at least iOS 16, across several years and multiple app releases. Earlier iOS versions are uncertain, and we cannot confirm that all historical occurrences share the same cause. Updates without networking-code changes can be followed by failures. A later update sometimes restores connectivity, but not consistently. Customer-reported recovery attempts: The app's wireless-data permissions appear enabled in Settings. Switching the app's network permission to another setting and back did not help users who reported trying it. Reset Network Settings also did not help users who reported trying it. Some users reported that deleting and reinstalling the app restored connectivity. At least one user reported that deletion and reinstallation did not help. These are customer reports, not controlled tests on our development devices. We would prefer a recovery that preserves local save data. Captured evidence from one affected installation: App version 1.89, build 1; Unity 2022.3.62f3. Device identifier: iPhone18,1; iOS 26.2.1. App in foreground. Capture time: 2026-09-07 13:04:31–13:04:32 UTC. An unfiltered Network.framework default-path monitor reported: status=unsatisfied reason=wifiDenied interface=Wi-Fi UnityWebRequest and a newly created native ephemeral NSURLSession both failed against our public HTTPS origin and Apple's independent test endpoint: https://www.apple.com/library/test/success.html The native requests failed after approximately 1 ms and 3 ms, with NSURLErrorDomain -1009, underlying kCFErrorDomainCFNetwork -1009, and no HTTP response. The native session allowed cellular, expensive and constrained network access, used normal TLS verification, and had waitsForConnectivity=false. It bypassed Unity's reachability precheck. CTCellularData changed from unknown to notRestricted. We understand this does not establish successful cellular connectivity or Wi-Fi permission. Important limitations: The native probes ran inside the same Unity-built process, not a separate standalone native app. The captured measurements demonstrate a Wi-Fi failure. Cellular failures and enabled Settings permissions are customer reports, not independently verified by these measurements. We cannot reliably reproduce the affected state on our development devices and do not have a focused Xcode project that reproduces it. An affected-device sysdiagnose is not yet available. Unity Customer QA reviewed this evidence, assessed it as an iOS network-policy issue rather than a Unity bug, and referred us to Apple. We are seeking Apple's investigation, not presenting that assessment as a confirmed root cause. The Code-Level Support form directed us to these forums because we cannot currently provide a focused reproducer. Questions: Which affected-device diagnostics or logging profiles would help identify why the effective network policy reports wifiDenied? How should we investigate an installation-specific issue when a new minimal app may not reproduce that installation state? Is there a supported, data-preserving recovery or application-side mitigation when permission changes and network resets do not help, and reinstallation is not consistently effective? We have diagnostic screenshots and relevant probe source available. Any customer system logs would be collected with consent and shared privately with Apple, not posted publicly. Thank you.

As part of the OpenJDK testing we run several regression tests, including for Java SE networking APIs. These APIs ultimately end up calling BSD socket functions. On macos, starting macos 26, including on recent 26.2 version, we have started seeing some unexplained but consistent exception from one of these BSD socket APIs. We receive a "ENOBUFS" errno (No buffer space available) when trying to construct a socket(). These exact same tests continue to pass on many other older versions of macos (including 15.7.x). After looking into this more, we have been able to narrow this down to a very trivial C code which is as follows (also attached): #include <stdio.h> #include <sys/socket.h> #include <string.h> #include <unistd.h> #include <sys/errno.h> static int create_socket(const int attempt_number) { const int fd = socket(AF_INET6, SOCK_STREAM, 0); if (fd < 0) { fprintf(stderr, "socket creation failed on attempt %d," " due to: %s\n", attempt_number, strerror(errno)); return fd; } return fd; } int main() { const unsigned int num_times = 250000; for (unsigned int i = 1; i <= num_times; i++) { const int fd = create_socket(i); if (fd < 0) { return -1; } close(fd); } fprintf(stderr, "successfully created and closed %d sockets\n", num_times); } The code very trivially creates a socket() and close()s it. It does this repeatedly in a loop for a certain number of iterations. Compiling this as: clang sockbufspaceerr.c -o sockbufspaceerr.o and running it as: ./sockbufspaceerr.o consistently generates an error as follows on macos 26.x: socket creation failed on attempt 160995, due to: No buffer space available The iteration number on which the socket() creation fails varies, but the issue does reproduce. Running the same on older versions of macos doesn't reproduce the issue and the program terminates normally after those many iterations. Looking at the xnu source that is made available for each macos release here https://opensource.apple.com/releases/, I see that for macos 26.x there have been changes in this kernel code and there appears to be some kind of memory accountability code introduced in this code path. However, looking at the reproducer/application code in question, I believe it uses the right set of functions to both create as well as release the resources, so I can't see why this should cause the above error in macos 26.x. Does this look like some issue that needs attention in the macos kernel and should I report it through feedback assitant tool?

I tried to compile the latest mDNSResponder (2881.120.11) for linux and discovered that it simply doesn't build: ../mDNSShared/uds_daemon.c: In function ‘resolve_result_callback’: ../mDNSShared/uds_daemon.c:3629:46: error: ‘request_state’ has no member named ‘resolve_awdl’ 3629 | const mDNSBool is_split_awdl_query = (req->resolve_awdl && question->InterfaceID == AWDLInterfaceID); | ^~ ../mDNSShared/uds_daemon.c:3629:89: error: ‘AWDLInterfaceID’ undeclared (first use in this function); did you mean ‘mDNSInterfaceID’? 3629 | const mDNSBool is_split_awdl_query = (req->resolve_awdl && question->InterfaceID == AWDLInterfaceID); | ^~~~~~~~~~~~~~~ This line was introduced in release 2881.60.4 (Jan 5, 2026), and all of the AWDL-related changes made to uds_daemon in that version look like unfinished code: The line shown above which references a non-existent struct field and nowhere-defined identifier/constant. Two functions in uds_daemon.c define a variable mDNSBool has_split_awdl_query = mDNSfalse; which is unused apart from its (unconditionally false) value being logged. The max-size-check for struct request_state in uds_daemon.h is increased but the struct itself wasn't changed (nor does the release introduce any other changes that might indirectly change the size of the struct) This code is common to all supported targets, so that means all four mDNSResponder releases done this year fail to build on all platforms. I'm a bit astonished how this even happens and has gone unnoticed for this long. Unfortunately it's not clear how to properly report this, the github repo has no issue tracker and the feedback assistant doesn't seem to have applicable options for this.

Hello, I am tracking a severe local networking regression on macOS Golden Gate 27.2 Developer Beta (build 26B5086k) running on MacBook Pro M4 Pro hardware. Despite negotiating a strong physical Wi-Fi connection with high PHY rates (1200+ Mbps) and excellent RSSI, actual throughput collapses dramatically and local gateway latency spikes uncontrollably whenever AWDL and AirDrop discovery are actively processing. Key Diagnostic Metrics Observed AWDL Manually Disabled: Executing sudo ifconfig awdl0 down completely drops packet loss to 0%, stabilizes gateway latency entirely, and restores baseline throughput. AirDrop Turned Off (AWDL Active): Disabling AirDrop via System Settings while keeping AWDL active stops the catastrophic latency spikes. This strongly suggests the trigger is linked directly to AirDrop's continuous background discovery/scanning activity rather than basic AWDL link states. Environment Isolation Performed Safe Mode: The issue persists cleanly while booted into macOS Safe Mode, ruling out third-party launch kexts, background daemons, or custom VPN software. Cross-AP Testing: The behavior follows the Mac across completely different access points, occurring on a dedicated Wi-Fi 7 home environment (tested across 5GHz and 6GHz channels) as well as an iPhone Personal Hotspot over cellular. Control Device: Same-location control testing with an iPhone shows perfect gigabit-class speeds, confirming the RF environment and network backhaul are perfectly healthy. I have already submitted a comprehensive sysdiagnose archive and wireless diagnostic log package directly to Apple. Feedback ID: FB24842970 Curious if anyone else with an M4 Pro on this build is seeing similar behavior. If this is happening on your end too, it might be worth submitting a bug report and referencing FB24842970 so Apple can group our logs together and look into a patch.

The documentation is pretty much blank. The same thing applies to the root NetworkProtocolOptions protocol. What are ContentType, LegacyMessage, BelowProtocol, Metadata, and ProtocolStorage? I can't determine if I should use these or not.

Hello! Users of my app observed behaviour that some apps stopped working after update to 15.7.8 via Beta channel with transparent proxy network extension on. The app receives Protocol not available error, and I see setsockopt SO_FLOW_DIVERT_TOKEN failed [42: Protocol not available] error in Console. To reproduce, create two rules in basic NETransparentProxyProvider: [[NENetworkRule alloc] initWithDestinationNetwork:nil prefix:0 protocol:NENetworkRuleProtocolTCP], [[NENetworkRule alloc] initWithDestinationNetwork:nil prefix:0 protocol:NENetworkRuleProtocolUDP], You may even return NO in handleNewFlow, it does not matter. After that, Safari won't open some sites, and Weather app will work unreliably. Do anyone knows any workaround for this problem? I've also create a relevant FB23788740.

Summary On macOS 26.6.2 (25G83) (Tahoe), Chrome fails to load pages hosted on private/local IP addresses (e.g. http://192.168.0.43/, a home AV receiver's web setup page) with ERR_ADDRESS_UNREACHABLE, while Safari loads the identical URL without issue on the same Mac, same network. ping to the target IP succeeds normally. System Settings > Privacy & Security > Local Network shows "Allow" for Chrome — but this is not what's actually being enforced. Traced the root cause to nesessionmanager stuck in an infinite retry loop when attempting to install/update NetworkExtension path-rule policies. Because the daemon never completes a successful policy install, nehelper (the actual enforcement point) continues serving a stale cached "denied" decision indefinitely, regardless of what the Settings UI shows or how many times the toggle is flipped. Key evidence Chrome netlog (chrome://net-export/) shows a genuine TCP connect attempt (not an early permission rejection): text TCP_CONNECT_ATTEMPT --> address = "192.168.0.43:80" -TCP_CONNECT_ATTEMPT --> os_error = 65 -TCP_CONNECT --> net_error = -109 (ERR_ADDRESS_UNREACHABLE) os_error = 65 is BSD EHOSTUNREACH, returned by the kernel at the connect() syscall. Unified log (log stream --predicate 'subsystem == "com.apple.networkextension"') shows the actual enforcement decision: text nehelper: UUID cache hit for com.google.Chrome nehelper: Local network denied by preference for Google Chrome (com.google.Chrome) This reproduced identically across multiple attempts, minutes apart, and survived sudo pkill -f nehelper — confirming the decision is persisted, not just an in-memory cache. While toggling the Local Network switch in System Settings, expecting a pathRules dump, the log instead showed: text NESMPathControllerSession[...]: No UUIDs in the cache for PathRuleDefaultNonSystemIdentifier, populating the cache from the path rules NESMPathControllerSession[...]: Will reinstall policies after 2000 milliseconds, retry 1 NESMPathControllerSession[...]: Will reinstall policies after 2000 milliseconds, retry 2 NESMPathControllerSession[...]: Will reinstall policies after 2000 milliseconds, retry 3 NESMPathControllerSession[...]: Will reinstall policies after 2000 milliseconds, retry 4 NESMPathControllerSession[...]: Will reinstall policies after 2000 milliseconds, retry 5 The retry counter kept incrementing with no observed successful completion, meaning any change made via the System Settings toggle can never actually propagate to nehelper. Also confirmed Local Network privacy is not TCC-backed at all: text $ sudo tccutil reset LocalNetwork tccutil: Failed to reset LocalNetwork $ sudo tccutil reset LocalNetwork com.google.Chrome tccutil: Failed to reset LocalNetwork approval status for com.google.Chrome Both fail outright rather than erroring on bad usage, confirming this permission lives entirely in the NetworkExtension path-rule system, with no supported reset command. What did not fix it Toggling the Settings UI switch off/on sudo tccutil reset SystemPolicyNetworkVolumes (wrong TCC service — doesn't apply here) sudo tccutil reset LocalNetwork (fails, see above) Full clean reinstall of Chrome, including all Application Support/Caches/Preferences Safe Mode boot sudo pkill -f nehelper Full normal system restart Launching Chrome with --no-sandbox (rules out Chromium's own internal sandbox as a factor — this is a system-level enforcement, not a Chromium-side block) Working fix Requires temporarily disabling SIP: text In macOS Recovery (csrutil only works from Recovery, not Safe Mode): csrutil disable Back in normal macOS: sudo rm /Library/Preferences/com.apple.networkextension.plist Back in Recovery: csrutil enable Restart normally. nesessionmanager rebuilds the NetworkExtension policy state from scratch on next boot. System Settings > Privacy & Security > Local Network shows a clean list afterward (also clears the separate, previously-known bug where every Chrome auto-update was creating a new duplicate entry in that list rather than updating the existing one). Chrome's next navigation attempt to a local IP correctly triggers a fresh permission prompt, and functions normally once granted. Why this matters Apple's own TN3179 states there's no supported way to reset an app's Local Network privilege to "undetermined." This bug compounds that: once nesessionmanager gets stuck in this retry loop, there is no path back to a working state short of disabling SIP and manually deleting a system preference file. The Settings UI also actively misrepresents the true enforcement state (shows "Allow" while nehelper enforces "denied") with no indication to the user that anything is wrong. This is likely not Chrome-specific — any app relying on Local Network access (smart-home apps, casting/streaming apps, IoT config tools) would hit the identical wall once a Mac's nesessionmanager enters this state. Also filed via Feedback Assistant. Happy to share the full decoded netlog trace if useful — didn't attach it here to keep this post scannable, but can paste the additional detail on request.

Hello, I'm desperately looking for a way to purge the contents of the Local Network allowlist in System Settings. Every version of a test app I've ever used gets an entry in there, and apparently so does each build of Chrome and Claude Code. Claude recommended I include the following context, and if there's a specific answer to that, great, but any way of purging this list would make me very happy. ==== Caution: slop below this line ==== macOS 27.0 (26A428), Apple silicon. The Local Network list has 471 entries, many dead: Chrome code_sign_clone paths that no longer exist, old ad-hoc builds, uninstalled apps. The pane can't remove any. Is there a supported way to remove entries or reset the list, short of Recovery? Editing /Library/Preferences/com.apple.networkextension.plist as root fails with EPERM, both rename-over and open-for-write. New files in that directory work. SIP is on, the file has no flags or xattrs, Full Disk Access didn't help, and there are no Sandbox/TCC denials in the log. What protects this file?

Hello everyone, I found an interesting post by a developer on social media that mentions that Apple has provided a new configuration profile. Is this a new feature? Does anyone have any additional information about it? And can anyone provide me with the link to download this profile?

We are having an issue with the Local Network permission pop-up not getting triggered for our apps that need to communicate with devices via local network interfaces/addresses. As we understand, apps using UDP should trigger this, causing macOS to prompt for access, or, if denied, fail to connect. However, we are facing issues with macOS not prompting this popup at all. Here are important and related points: Our application is packaged as a .app package and distributed independently (not on the App Store). The application controls hardware that we manufacture. In order to find the hardware on the network, we send a UDP broadcast with a message for our hardware on the local network, and the hardware responds with a message back. However, the popup (to ask for permission) never shows up. The application is not able to find the hardware device. It is interesting to note that data is still sent out to the network (without the popup) but we receive back the wrong data. The behaviour is consistent macOS Sequoia (and above) with both Apple And Intel silicon. Workarounds that have been tried: Manual Authorization: One solution suggested in various blogs was to go to "Settings → Privacy and Security-> Local network", find your application and grant access. However, the application never shows up in the list here. Firewall: No difference is seen in behaviour with firewall being ON OR OFF. Setting NSLocalNetworkUsageDescription: We have also tried setting the Info.plist adding the NSLocalNetworkUsageDescription with a meaningful string and updating the NSBonjourServices. Running Via terminal (WORKS): Running the application via terminal sees no issues. The application runs correctly and is able to send UDP and receive correct data (and find the devices on the network). But this is not an appropriate solution. How can we get this bug/issue fixed in macOS Sequoia (and above)? Are there any other solutions/workarounds that we can try on our end?

We have a NEPacketTunnelProvider extension that intercepts and modifies DNS responses for specific hostnames as part of its normal operation. On iOS 27, we are seeing this interception being intermittently bypassed. Our extension still receives the DNS query, builds a response, and returns it promptly, but the client occasionally proceeds using a different address, presumably the actual DNS resolution result. This behavior does not reproduce on iOS 26 or earlier. The timing in our logs appears to correlate with the new Connectivity Assist feature (Settings → Wi-Fi), which Apple describes as using cellular data alongside Wi-Fi to improve reliability. Our suspicion is that Connectivity Assist may be performing DNS resolution over a cellular path in parallel, outside the tunnel, causing that resolution path to bypass our provider entirely. We have ruled out response timing and response format issues on our side. Varying the speed and format of our responses does not affect the outcome, suggesting that the behavior is occurring at a layer above the tunnel provider. We have the following questions: Does Connectivity Assist perform DNS resolution on a network path that can bypass an active NEPacketTunnelProvider? Is there any API, entitlement, or supported mechanism to disable Connectivity Assist for an app, or to ensure that all DNS resolution is routed through the active tunnel, similar to previous Wi-Fi Assist opt-out capabilities? Would a NEDNSProxyProvider-based DNS proxy be affected in the same way, or does it operate at a layer that Connectivity Assist cannot bypass? Any guidance, references to relevant documentation, WWDC session content, or confirmation of the expected behavior would be greatly appreciated.

I applied on the Multicast Networking Entitlement Request site, but I did not receive a response email. How long does a response usually take?

Hello, I am investigating a roaming network selection use case on iPhone and would like to know whether Apple provides any supported API, entitlement, carrier capability, or carrier-specific integration that allows an application or a mobile network operator to access or control PLMN selection while roaming. My specific use case is: Device: iPhone 17 iOS: 26.6.1 Home operator: Orange France Roaming country: Switzerland Automatically selected roaming network: Salt Preferred roaming network: Swisscom At this location, Salt has very poor cellular coverage while Swisscom has excellent coverage. The user can manually select Swisscom through: Settings → Cellular → Network Selection → Swisscom I would like to determine whether there is any supported mechanism for a carrier or a carrier-authorized application to: Read the currently selected roaming PLMN. Obtain the available roaming PLMNs. Programmatically select a specific PLMN. Configure a preferred roaming PLMN. Ask the modem to prefer one roaming partner over another. Access any carrier-only/private entitlement that provides such functionality. For example, could an authorized Orange carrier application or carrier integration request that Swisscom (MCC 228 / MNC 01) be preferred over Salt (MCC 228 / MNC 03) while roaming in Switzerland? I understand that Core Telephony provides access to some carrier information and that certain capabilities require Apple-granted entitlements. If this functionality is not available to third-party applications, is there a carrier integration, carrier configuration, SIM/eSIM profile mechanism, or other Apple-supported mechanism that can influence the preferred roaming PLMN? I am specifically looking for a supported solution and not a jailbreak or other unsupported/private API. Thank you.

I am developing an iOS application for carrier network testing and diagnostics, and I need to access the following cellular, carrier, subscriber, and device information: RSRP RSRQ SINR RSSI PCI Cell ID LTE/5G Band EARFCN / NRARFCN Carrier name Country code MCC MNC Mobile/subscriber number IMEI Enable/Disable/connect wifi Enable/Disable hotspot Insert/update/delete e-sim I understand that some or all of this information is not available through Apple’s public iOS APIs. My question is: If I request Apple’s Interoperability Access or a carrier-related entitlement for an application developed specifically for carrier network testing and diagnostics, can these APIs/data become available? If yes, could someone please clarify: Which of the above data points can be accessed with carrier-related entitlements? Which specific entitlements or APIs are required? Are RSRP, RSRQ, SINR, RSSI, PCI, Cell ID, Band, and EARFCN/NRARFCN available through any Apple-approved entitlement? Can carrier information such as carrier name, MCC, MNC, and country code be accessed? Is mobile/subscriber number accessible? Is IMEI accessible with a carrier entitlement? Is there a specific Apple WWDR/Interoperability request process for these requirements? This is for a legitimate carrier testing/diagnostics application. I would appreciate any clear guidance on what is technically possible on current iOS versions and which Apple approval/entitlement process I should follow.