General:
Forums subtopic: App & System Services > Networking
TN3151 Choosing the right networking API
Networking Overview document — Despite the fact that this is in the archive, this is still really useful.
TLS for App Developers forums post
Choosing a Network Debugging Tool documentation
WWDC 2019 Session 712 Advances in Networking, Part 1 — This explains the concept of constrained networking, which is Apple’s preferred solution to questions like How do I check whether I’m on Wi-Fi?
TN3135 Low-level networking on watchOS
TN3179 Understanding local network privacy
Adapt to changing network conditions tech talk
Understanding Also-Ran Connections forums post
Extra-ordinary Networking forums post
Foundation networking:
Forums tags: Foundation, CFNetwork
URL Loading System documentation — NSURLSession, or URLSession in Swift, is the recommended API for HTTP[S] on Apple platforms.
Moving to Fewer, Larger Transfers forums post
Testing Background Session Code forums post
Network framework:
Forums tag: Network
Network framework documentation — Network framework is the recommended API for TCP, UDP, and QUIC on Apple platforms.
Building a custom peer-to-peer protocol sample code (aka TicTacToe)
Implementing netcat with Network Framework sample code (aka nwcat)
Configuring a Wi-Fi accessory to join a network sample code
Moving from Multipeer Connectivity to Network Framework forums post
NWEndpoint History and Advice forums post
Network Extension (including Wi-Fi on iOS):
See Network Extension Resources
Wi-Fi Fundamentals
TN3111 iOS Wi-Fi API overview
Wi-Fi Aware framework documentation
Wi-Fi on macOS:
Forums tag: Core WLAN
Core WLAN framework documentation
Wi-Fi Fundamentals
Secure networking:
Forums tags: Security
Apple Platform Security support document
Preventing Insecure Network Connections documentation — This is all about App Transport Security (ATS).
WWDC 2017 Session 701 Your Apps and Evolving Network Security Standards [1] — This is generally interesting, but the section starting at 17:40 is, AFAIK, the best information from Apple about how certificate revocation works on modern systems.
Available trusted root certificates for Apple operating systems support article
Requirements for trusted certificates in iOS 13 and macOS 10.15 support article
About upcoming limits on trusted certificates support article
Apple’s Certificate Transparency policy support article
What’s new for enterprise in iOS 18 support article — This discusses new key usage requirements.
Technote 2232 HTTPS Server Trust Evaluation
Technote 2326 Creating Certificates for TLS Testing
QA1948 HTTPS and Test Servers
Miscellaneous:
More network-related forums tags: 5G, QUIC, Bonjour
On FTP forums post
Using the Multicast Networking Additional Capability forums post
Investigating Network Latency Problems forums post
WirelessInsights framework documentation
iOS Network Signal Strength forums post
Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
[1] This video is no longer available from Apple, but the URL should help you locate other sources of this info.
Networking
RSS for tagExplore the networking protocols and technologies used by the device to connect to Wi-Fi networks, Bluetooth devices, and cellular data services.
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Several of my users are reporting on at lest recent and current versions of iOS the value from one characteristic can be swapped with another.
Originally I thought this was a library issue but it doesn't happen on Android and now a user with two iPhones using the exact same app and iOS 26.3 on both has the issue on one phone but not the other.
I've gone into more detail here which also includes a little data dumping to prove the values between characteristics can be mixed up.
https://github.com/dotintent/react-native-ble-plx/issues/1316
One user reported cycling Bluetooth on/off fixed the issue but the latest user says it does not.
For the peripheral the services can only change if the device enters firmware update mode (in which case the service UUID is different). Otherwise the characteristics on a service never change. This would make it a strange one to be caching related since the cache should always be correct.
I'm using NEPacketTunnelProvider to intercept DNS queries, forward them upstream,
and inject the responses back via writePacketObjects().
This works correctly for responses under ~500 bytes. For larger responses (~893
bytes, e.g. DNS CERT records), writePacketObjects() returns without error but
mDNSResponder never receives the packet — it retries 3–4 times and then times out.
What I have verified:
IP and UDP checksums are correct
UDP length and IP total length fields are correct
Maximum packet size (MTU) set to 1500 in NEIPv4Settings/NEIPv6Settings
Approaches tried:
Injecting the full 921-byte packet — writePacketObjects() succeeds but the
packet never reaches mDNSResponder
IP-level fragmentation — fragments appear to be silently dropped
Setting the TC (truncation) bit — mDNSResponder does not retry over TCP
Truncating the response to ≤512 bytes — the packet arrives but the data is
incomplete
Questions:
Is there a supported way to deliver a DNS response larger than 512 bytes
through NEPacketTunnelFlow?
Does NEPacketTunnelProvider impose an undocumented packet size limit below
the configured MTU?
Does mDNSResponder silently discard responses larger than 512 bytes when the
original query had no EDNS0 OPT record? Is there a way to signal that larger
responses are supported?
Are IP-level fragments reliably delivered through writePacketObjects()?
Tested on iOS 26.3, physical device.
Topic:
App & System Services
SubTopic:
Networking
We have a VPN app that uses NEPacketTunnelProvider with includeAllNetworks = true. We've encountered an issue where push notifications are not delivered over Wi-Fi while the tunnel is active in a pre-MFA quarantine state (tunnel is up but traffic is blocked on server side), regardless of whether excludeAPNS is set to true or false.
Observed behavior
Wi-Fi excludeAPNS = true - Notifications not delivered
Wi-Fi excludeAPNS = false - Notifications not delivered
Cellular excludeAPNS = true - Notifications delivered
Cellular excludeAPNS = false - Notifications not delivered
On cellular, the behavior matches our expectations: setting excludeAPNS = true allows APNS traffic to bypass the tunnel and notifications arrive; setting it to false routes APNS through the tunnel and notifications are blocked (as expected for a non-forwarding tunnel). On Wi-Fi, notifications fail to deliver in both cases.
Our question
Is this expected behavior when includeAllNetworks is enabled on Wi-Fi, or is this a known issue / bug with APNS delivery? Is there something else in the Wi-Fi networking path that includeAllNetworks affects beyond routing, which could prevent APNS from functioning even when the traffic is excluded from the tunnel?
Sample Project
Below is the minimal code that reproduces this issue. The project has two targets: a main app and a Network Extension. The tunnel provider captures all IPv4 and IPv6 traffic via default routes but does not forward packets — simulating a pre-MFA quarantine state. The main app configures the tunnel with includeAllNetworks = true and provides a UI toggle for excludeAPNS.
PacketTunnelProvider.swift (Network Extension target):
import NetworkExtension
class PacketTunnelProvider: NEPacketTunnelProvider {
override func startTunnel(options: [String : NSObject]?, completionHandler: @escaping (Error?) -> Void) {
let settings = NEPacketTunnelNetworkSettings(tunnelRemoteAddress: "127.0.0.1")
let ipv4 = NEIPv4Settings(addresses: ["198.51.100.1"], subnetMasks: ["255.255.255.0"])
ipv4.includedRoutes = [NEIPv4Route.default()]
settings.ipv4Settings = ipv4
let ipv6 = NEIPv6Settings(addresses: ["fd00::1"], networkPrefixLengths: [64])
ipv6.includedRoutes = [NEIPv6Route.default()]
settings.ipv6Settings = ipv6
let dns = NEDNSSettings(servers: ["198.51.100.1"])
settings.dnsSettings = dns
settings.mtu = 1400
setTunnelNetworkSettings(settings) { error in
if let error = error {
completionHandler(error)
return
}
self.readPackets()
completionHandler(nil)
}
}
private func readPackets() {
packetFlow.readPackets { [weak self] packets, protocols in
self?.readPackets()
}
}
override func stopTunnel(with reason: NEProviderStopReason, completionHandler: @escaping () -> Void) {
completionHandler()
}
override func handleAppMessage(_ messageData: Data, completionHandler: ((Data?) -> Void)?) {
if let handler = completionHandler {
handler(messageData)
}
}
override func sleep(completionHandler: @escaping () -> Void) {
completionHandler()
}
override func wake() {
}
}
ContentView.swift (Main app target) — trimmed to essentials:
import SwiftUI
import NetworkExtension
struct ContentView: View {
@State private var excludeAPNs = false
@State private var manager: NETunnelProviderManager?
var body: some View {
VStack {
Toggle("Exclude APNs", isOn: $excludeAPNs)
.onChange(of: excludeAPNs) { Task { await saveAndReload() } }
Button("Connect") { Task { await toggleVPN() } }
}
.padding()
.task { await loadManager() }
}
private func loadManager() async {
let managers = try? await NETunnelProviderManager.loadAllFromPreferences()
if let existing = managers?.first {
manager = existing
} else {
let m = NETunnelProviderManager()
let proto = NETunnelProviderProtocol()
proto.providerBundleIdentifier = "<your-extension-bundle-id>"
proto.serverAddress = "127.0.0.1"
proto.includeAllNetworks = true
proto.excludeAPNs = excludeAPNs
m.protocolConfiguration = proto
m.localizedDescription = "TestVPN"
m.isEnabled = true
try? await m.saveToPreferences()
try? await m.loadFromPreferences()
manager = m
}
if let proto = manager?.protocolConfiguration as? NETunnelProviderProtocol {
excludeAPNs = proto.excludeAPNs
}
}
private func saveAndReload() async {
guard let manager else { return }
if let proto = manager.protocolConfiguration as? NETunnelProviderProtocol {
proto.includeAllNetworks = true
proto.excludeAPNs = excludeAPNs
}
manager.isEnabled = true
try? await manager.saveToPreferences()
try? await manager.loadFromPreferences()
}
private func toggleVPN() async {
guard let manager else { return }
if manager.connection.status == .connected {
manager.connection.stopVPNTunnel()
} else {
await saveAndReload()
try? manager.connection.startVPNTunnel()
}
}
}
Steps to reproduce
Build and run the sample project with above code on a physical iOS device. Connect to a Wi-Fi network.
Set excludeAPNS = true using the toggle and tap Connect.
Send a push notification to the device to a test app with remote notification capability (e.g., via a test push service or the push notification console).
Observe that the notification is not delivered.
Disconnect. Switch to cellular. Reconnect with the same settings.
Send the same push notification — observe that it is delivered.
Environment
iOS 26.2
Xcode 26.2
Physical device (iPhone 15 Pro)
Is it somehow possible to get the transport layer (UDP and TCP) payload amounts for TLS or QUIC connections established via the Network framework? (From within the app itself that establishes the connections.)
I am currently using the ntstat.h kernel socket calls, but I hope there is a simpler solution.
With ntstat, I have not yet been able to observe a specific connection. I have to search for the connection I am looking in all (userspace) connections.
Since updating to macOS 26.4 developerbeta 2 I've been getting full loss of dns resolution. I am not running a VPN or any network extensions that I am aware of.
I'm not sure how to report this in the feedback utility as I cannot find an appropriate category for it. Happy to file it if someone can give an appropriate suggestion - the closest I could see was Wi-Fi but that wanted Wi-Fi logs for the issue, which I do not believe to be needed as this is not a Wi-Fi connectivity issue.
Running
dig example.com +short
nslookup example.com
ping example.com
Gives the following output
104.18.27.120
104.18.26.120
Server: 10.0.1.1
Address: 10.0.1.1#53 \
Non-authoritative answer:
Name: example.com
Address: 104.18.26.120
Name: example.com
Address: 104.18.27.120 \
ping: cannot resolve example.com: Unknown host
This shows it's not an issue with my local network and that core networking is working, but something in the mDNSResponder/dns stack of macOS is failing. This causes all apps/browsers that do not implement their own DNS lookups to fail (Chrome still works).
Sometimes the issue clears after running the following commands (for a period), sometimes it does not. A restart always resolves the issue temporarily.
sudo killall -9 mDNSResponder
sudo killall -9 mDNSResponderHelper
sudo dscacheutil -flushcache
sudo ifconfig en0 down
sudo ifconfig en0 up
Topic:
App & System Services
SubTopic:
Networking
I’m encountering a persistent issue with my Network Extension (specifically NEFilterDataProvider) and would really appreciate any insights.
The extension generally works as expected, but after some time — especially after sleep/wake cycles or network changes — a global network outage occurs. During this state, no network traffic works: pings fail, browsers can’t load pages, etc. As soon as I stop the extension (by disabling it in System Preferences), the network immediately recovers. If I re-enable it, the outage returns instantly.
I’ve also noticed that once this happens, the extension stops receiving callbacks like handleNewFlow(), and reinstalling the app or restarting the extension doesn’t help. The only thing that resolves the issue is rebooting the system. After reboot, the extension works fine again — until the problem reoccurs later.
I asked AI about this behavior, and it suggested the possibility that the kernel might have marked the extension as untrusted, causing the system to intentionally block all network traffic as a safety mechanism.
Has anyone experienced similar behavior with NEFilterDataProvider? Could there be a way to detect or prevent this state without rebooting? Is there any logging or diagnostic data I should collect when it happens again?
Any guidance or pointers would be greatly appreciated. Thanks in advance!
Hello Apple Support Team,
We are seeing a production crash on iOS 26 devices that appears to originate from Apple system frameworks rather than application code.
1. Crash Details
OS Version: iOS 26.x
App built with: Xcode 16
Devices: Multiple models (not device-specific)
Exception Type: SIGSEGV SEGV_ACCERR
Fault Address: 0x0000000000000100
Crashed Thread: 4 (network background queue)
Crash trace summary:
Last Exception :
0 libobjc.A.dylib _objc_release_x8 + 8
1 libboringssl.dylib _nw_protocol_boringssl_deallocate_options + 92
2 Network 0x000000019695207c 0x00000001968dc000 + 483452
3 libswiftCore.dylib __swift_release_dealloc + 56
4 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152
5 Network 0x0000000196951f6c 0x00000001968dc000 + 483180
6 Network 0x0000000196952000 0x00000001968dc000 + 483328
7 libswiftCore.dylib __swift_release_dealloc + 56
8 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152
9 libswiftCore.dylib void multiPayloadEnumFN<&handleRefCountsDestroy>(swift::TargetMetadata<swift::InProcess> const*, swift::LayoutStringReader1&, unsigned long&, unsigned char*) + 248
10 libswiftCore.dylib swift::swift_cvw_arrayDestroy(swift::OpaqueValue*, unsigned long, unsigned long, swift::TargetMetadata<swift::InProcess> const*) + 1172
11 libswiftCore.dylib _$sSp12deinitialize5countSvSi_tF + 40
12 CollectionsInternal ___swift_instantiateGenericMetadata + 1236
13 CollectionsInternal ___swift_instantiateGenericMetadata + 388
14 CollectionsInternal ___swift_instantiateGenericMetadata + 1044
15 libswiftCore.dylib __swift_release_dealloc + 56
16 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152
17 Network 0x000000019695f9fc 0x00000001968dc000 + 539132
18 Network 0x000000019695f9bc 0x00000001968dc000 + 539068
19 libswiftCore.dylib __swift_release_dealloc + 56
20 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152
21 libswiftCore.dylib swift_cvw_destroyImpl(swift::OpaqueValue*, swift::TargetMetadata<swift::InProcess> const*) + 212
22 Network 0x0000000196def5d8 0x00000001968dc000 + 5322200
23 Network 0x0000000196ded130 0x00000001968dc000 + 5312816
24 libswiftCore.dylib __swift_release_dealloc + 56
25 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152
26 Network 0x000000019695fde0 0x00000001968dc000 + 540128
27 libobjc.A.dylib object_cxxDestructFromClass(objc_object*, objc_class*) + 116
28 libobjc.A.dylib objc_destructInstance_nonnull_realized(objc_object*) + 76
29 libobjc.A.dylib __objc_rootDealloc + 72
30 Network 0x000000019695f99c 0x00000001968dc000 + 539036
31 Network 0x000000019695fae4 0x00000001968dc000 + 539364
32 Network 0x0000000196b078b8 0x00000001968dc000 + 2275512
33 libobjc.A.dylib object_cxxDestructFromClass(objc_object*, objc_class*) + 116
34 libobjc.A.dylib objc_destructInstance_nonnull_realized(objc_object*) + 76
35 libobjc.A.dylib __objc_rootDealloc + 72
36 Network 0x0000000196b07658 0x00000001968dc000 + 2274904
37 Network 0x00000001968e51d4 nw_queue_context_async_if_needed + 92
38 Network 0x0000000197686ea0 0x00000001968dc000 + 14331552
39 libswiftCore.dylib swift::swift_cvw_arrayDestroy(swift::OpaqueValue*, unsigned long, unsigned long, swift::TargetMetadata<swift::InProcess> const*) + 436
40 libswiftCore.dylib _$sSp12deinitialize5countSvSi_tF + 40
41 CollectionsInternal ___swift_instantiateGenericMetadata + 1236
42 CollectionsInternal ___swift_instantiateGenericMetadata + 388
43 CollectionsInternal ___swift_instantiateGenericMetadata + 1044
44 libswiftCore.dylib __swift_release_dealloc + 56
45 libswiftCore.dylib bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1> >::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152
46 Network 0x000000019694a010 0x00000001968dc000 + 450576
47 libobjc.A.dylib object_cxxDestructFromClass(objc_object*, objc_class*) + 116
48 libobjc.A.dylib objc_destructInstance_nonnull_realized(objc_object*) + 76
49 libobjc.A.dylib __objc_rootDealloc + 72
50 Network 0x0000000196a330e0 0x00000001968dc000 + 1405152
51 Network 0x00000001974378e0 0x00000001968dc000 + 11909344
52 Network 0x0000000196a17178 0x00000001968dc000 + 1290616
53 libdispatch.dylib __dispatch_call_block_and_release + 32
54 libdispatch.dylib __dispatch_client_callout + 16
55 libdispatch.dylib _dispatch_workloop_invoke.cold.4 + 32
56 libdispatch.dylib __dispatch_workloop_invoke + 1980
57 libdispatch.dylib __dispatch_root_queue_drain_deferred_wlh + 292
58 libdispatch.dylib __dispatch_workloop_worker_thread + 692
59 libsystem_pthread.dylib __pthread_wqthread + 292
------
Exception Type: SIGSEGV SEGV_ACCERR
Exception Codes: fault addr: 0x0000000000000100
Crashed Thread: 4
2. Behavior & Context
The crash occurs during normal HTTPS networking using standard URLSession (no direct usage of Network.framework nor boringssl APIs).
It appears to be triggered during QUIC connection establishment or TLS fallback.
The stack trace contains no application code frames — all symbols are from system libraries.
The crash strongly indicates double-free, over-release, or dangling pointer inside nw_protocol_boringssl_options deallocation.
3. Questions for Apple
Is this a known issue in iOS 26 within Network.framework / boringssl related to nw_protocol_boringssl_deallocate_options?
What is the root cause of the over‑release / invalid objc_release in this path?
Is there a workaround we can implement from the app side (e.g., disabling QUIC, adjusting TLS settings, or queue configuration)?
Do you have a target iOS version or patch where this issue will be fixed?
We can provide full crash logs and additional metrics upon request.
4. Additional Information
Developed using Swift 5, with a deployment target of iOS 12+.
Thank you for your support.
Topic:
App & System Services
SubTopic:
Networking
Dear Apple Developer Technical Support,
I am currently developing a macOS network filtering solution using NetworkExtension with NEFilterDataProvider.
During implementation of the handleOutboundData logic, we are using the following verdict:
NEFilterNewFlowVerdict.filterDataVerdict(
withFilterInbound: true,
peekInboundBytes: InboundPeekBytes,
filterOutbound: true,
peekOutboundBytes: OutboundPeekBytes
)
However, we have encountered an issue when SMB traffic is involved.
When SMB protocol communication occurs, the network connection occasionally becomes unresponsive or appears to stall when peekOutboundBytes is set to a large value.
Through testing, we observed the following behavior:
On some systems, reducing the peekOutboundBytes value allows SMB communication to proceed normally.
On other systems, even relatively small values can still cause the SMB connection to stall.
This behavior appears inconsistent across different macOS environments.
Because of this, we would like to clarify the following:
Is there a documented or recommended maximum value for peekOutboundBytes when using NEFilterNewFlowVerdict.filterDataVerdict?
Are there any internal limits or constraints within NetworkExtension that could cause SMB traffic to stall when the peek buffer size is too large?
Are there best practices for selecting appropriate peekInboundBytes / peekOutboundBytes values when filtering high-throughput protocols such as SMB?
If necessary, we can provide additional information such as macOS version, test environment details, and logs.
Thank you for your assistance.
Best regards,
sangho
I'm building a macOS network monitor using NEFilterDataProvider as a system extension, distributed with Developer ID signing. On macOS 26.3 (Tahoe), sysextd consistently rejects the activation request with "no policy, cannot allow apps outside /Applications" — despite the app being in /Applications and passing every verification check.
I'm aware of the known Xcode NE signing bug (r. 108838909) and have followed the manual signing process from Exporting a Developer ID Network Extension. I've also tried both xcodebuild build and xcodebuild archive workflows — identical failure.
Environment
macOS
26.3 (25D125), SIP enabled
Xcode
26.3 (17C529)
Hardware
Apple M2 Pro
Certificate
Developer ID Application (issued Jan 30, 2026 — 27 days old)
MDM/Profiles
None installed
Signing & Verification (all pass)
$ spctl -a -vv /Applications/Chakshu.app
/Applications/Chakshu.app: accepted
source=Notarized Developer ID
origin=Developer ID Application: ROBIN SHARMA (R65679C4F3)
$ codesign --verify --deep --strict -vv /Applications/Chakshu.app
/Applications/Chakshu.app: valid on disk
/Applications/Chakshu.app: satisfies its Designated Requirement
$ xcrun stapler validate /Applications/Chakshu.app
The validate action worked!
App signing:
Authority=Developer ID Application: ROBIN SHARMA (R65679C4F3)
Authority=Developer ID Certification Authority
Authority=Apple Root CA
TeamIdentifier=R65679C4F3
Runtime Version=26.2.0
Notarization Ticket=stapled
App entitlements:
com.apple.application-identifier = R65679C4F3.dev.indrasvat.chakshu
com.apple.developer.team-identifier = R65679C4F3
com.apple.developer.system-extension.install = true
com.apple.developer.networking.networkextension = [content-filter-provider-systemextension]
keychain-access-groups = [R65679C4F3.*]
Extension signing: Same Developer ID authority, same team, same timestamp. Extension entitlements match (minus system-extension.install). Developer ID provisioning profiles are embedded in both app and extension.
What sysextd logs
Captured Feb 26, 2026 from log stream --predicate 'process == "sysextd"':
sysextd [com.apple.sx:XPC] client activation request for dev.indrasvat.chakshu.filter
sysextd attempting to realize extension with identifier dev.indrasvat.chakshu.filter
sysextd (Security) SecKeyVerifySignature ← pass (×2)
sysextd (Security) SecTrustEvaluateIfNecessary ← pass (×2)
sysextd [com.apple.xpc:connection] activating connection: name=com.apple.CodeSigningHelper
sysextd [com.apple.xpc:connection] invalidated after the last release
sysextd no policy, cannot allow apps outside /Applications
sysextd [com.apple.sx:XPC] client connection invalidated
Signature and trust evaluation pass. CodeSigningHelper completes. Then the policy check fails. The app receives OSSystemExtensionError code 4 (extensionNotFound).
What I've tried and ruled out
Build process:
Approach
Result
xcodebuild build -configuration Release + manual re-sign
Same failure
xcodebuild archive + export from archive + manual re-sign (per thread/737894)
Same failure
Minimal hand-crafted Xcode project (no xcodegen, trivial code)
Same failure
Both workflows follow Quinn's process exactly: build with Apple Development → copy app → embed Developer ID provisioning profiles → re-sign inside-out (extension first, then app) with -systemextension suffix entitlements → notarize → staple → install to /Applications.
System-level checks:
Rebooting — no change
Killing sysextd — no change
Removing com.apple.quarantine xattr — no change
chown root:wheel on app bundle — no change
lsregister -r (reset Launch Services) — no change
Waiting 27 days for certificate propagation — no change
Reinstalling via Finder drag-to-Applications — no change
No MDM or configuration profiles installed
/Library/SystemExtensions/db.plist shows extensionPolicies: [] (empty)
Key observation
Pre-existing network extensions activated before macOS 26 work fine on this machine. For example, Tailscale's NEPacketTunnelProvider shows state: activated_enabled in the system extensions database — it was activated on a prior macOS version and is still running. Only new system extension activations fail.
I've seen similar Tahoe-specific reports from LuLu (same NEFilterDataProvider type, Developer ID distribution):
LuLu #825
LuLu #831
Questions
Is this a known regression in macOS 26's sysextd policy evaluation for new Developer ID system extension activations?
sysextd's policy check fails after all signature and trust evaluation succeeds. Is there a separate trust/policy path that sysextd consults beyond what spctl, codesign, and CodeSigningHelper verify?
Is there anything else I should be checking?
I have a sysdiagnose captured immediately after the failure, a minimal reproducer project, and full raw sysextd logs available on request.
Hi,
On macOS 26.4 Beta (25E5218f) (macOS Tahoe 26 Developer Beta ), the network filter causes network failures or slowdowns. This manifests as Chrome failing to access websites, while Safari can access the same websites without issue. The affected websites can be pinged locally.
My situation is similar to this situation.The same question link is: https://github.com/objective-see/LuLu/issues/836
Have you been paying attention to this issue? Hopefully, it can be fixed in the official release.
Thank you.
Hi Apple Network Team,
Good day.
Recently we are experiencing some issues that when iOS or iPad OS connected to a Wi-Fi with captive portal, iOS sometimes failed to launch the full captive portal website.
Based on TCPDump and WLAN dump logs, when this failure happened, we only see web client on iOS queried AAAA and HTTPS DNS queries without A query. Not all the websites are supporting and being hosted on both IPv4 and IPv6 servers. Is there a know bug on iOS and iPad OS side including OS version >= 36.2.
Topic:
App & System Services
SubTopic:
Networking
Dear Apple Developer Support Team,
I am writing to inquire about the process for obtaining approval for the following entitlement in my iOS/macOS app:
<key>com.apple.developer.networking.networkextension</key>
<array>
<string>content-filter-provider</string>
</array>
Specifically, I would like guidance on:
The steps required to submit a request for this entitlement.
Any necessary documentation or justification that needs to be provided to Apple.
Typical review timelines and approval criteria.
Any restrictions or compliance requirements associated with this entitlement.
Our app intends to implement a content filtering functionality to enhance network security and user safety. We want to ensure full compliance with Apple’s policies and guidelines.
Could you please provide detailed instructions or point us to the relevant resources to initiate this approval process?
Thank you for your assistance.
We are currently experiencing an issue that occurs only on iPhone 17 models.
In our app, after connecting to an external device, users can download multiple video files stored on the device. When downloading several videos consecutively, the device consistently stops receiving responses midway through the process. As a result, no response is returned, and the connection between the app and the device is eventually lost.
This issue does not occur on any iPhone models prior to iPhone 17.
It is reproducible across all iPhone 17 devices within our company.
This is a critical issue, and we need urgent assistance.
The main error logs show two patterns:
• Connection loss
• Timeout
At the OS level, the only error codes we receive are:
• -1005 (Network connection lost)
• -1001 (Request timed out)
Unfortunately, we are unable to obtain more detailed error information beyond these codes, which makes further debugging difficult.
We have attached the relevant logs below.
We would greatly appreciate any guidance on how to further investigate or resolve this issue.
310.0 / :: 81 % ::: 251.21481481481482
310.0 / :: 82 % ::: 254.23280423280423
310.0 / :: 83 % ::: 257.3820105820106
310.0 / :: 84 % ::: 260.4
KeepAlive SEND id=423F1336-6239-4B3B-9414-5A987D85D564 at=2026-02-24T12:56:43Z timeout=60.000000s
current: D20-Q2-PLUS, ssid: D20-Q2-PLUS_136a63
KeepAlive SKIP (in-flight)
tcp_output [C10.1.1:3] flags=[R.] seq=4017430266, ack=4146413113, win=2048 state=CLOSED rcv_nxt=4146413113, snd_una=4017429847
nw_read_request_report [C10] Receive failed with error "Operation timed out"
nw_flow_add_write_request [C10 192.168.000.0:443 failed parent-flow (satisfied (Path is satisfied), interface: en0[802.11], ipv4,
dns, uses wifi, LQM: good)] cannot accept write requests
nw_write_request_report [C10] Send failed with error "Socket is not connected"
Task <5BDBE621-329A-45E9-B236-9C173E92A41F>.<7> HTTP load failed, 361/0 bytes (error code: -1005 [4:-4])
Task <5BDBE621-329A-45E9-B236-9C173E92A41F>.<7> finished with error [-1005] Error Domain=NSURLErrorDomain Code=-1005 "The network
connection was lost." UserInfo={_kCFStreamErrorCodeKey=-4, NSUnderlyingError=0x13e632160 {Error Domain=kCFErrorDomainCFNetwork
Code=-1005 "(null)" UserInfo={NSErrorPeerAddressKey=<CFData 0x14cfe5a90 [0x201746068]>{length = 16, capacity = 16, bytes =
0x100201bbc0a86f010000000000000000}, _kCFStreamErrorCodeKey=-4, _kCFStreamErrorDomainKey=4}},
_NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <5BDBE621-329A-45E9-B236-9C173E92A41F>.<7>,
_NSURLErrorRelatedURLSessionTaskErrorKey=(
"LocalDataTask <5BDBE621-329A-45E9-B236-9C173E92A41F>.<7>"
), NSLocalizedDescription=The network connection was lost., NSErrorFailingURLStringKey=https://192.168.000.0/keepalive,
NSErrorFailingURLKey=https://192.168.000.0/keepalive, _kCFStreamErrorDomainKey=4}
KeepAlive FAIL id=423F1336-6239-4B3B-9414-5A987D85D564 elapsed=29.203s status=-1
error=Optional(Alamofire.AFError.sessionTaskFailed(error: Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost."
UserInfo={_kCFStreamErrorCodeKey=-4, NSUnderlyingError=0x13e632160 {Error Domain=kCFErrorDomainCFNetwork Code=-1005 "(null)"
UserInfo={NSErrorPeerAddressKey=<CFData 0x14cfe5a90 [0x201746068]>{length = 16, capacity = 16, bytes =
0x100201bbc0a86f010000000000000000}, _kCFStreamErrorCodeKey=-4, _kCFStreamErrorDomainKey=4}},
), NSLocalizedDescription=The network connection was lost.,
KeepAlive FAIL
1001 Log
KeepAlive SEND id=FC433405-C1F7-47EF-AF9E-D12E67B071FA at=2026-02-24T12:22:38Z timeout=60.000000s
current: D20-Q2-PLUS, ssid: VUEROID_D20-Q2-PLUS_136a63
KeepAlive FAIL id=FC433405-C1F7-47EF-AF9E-D12E67B071FA elapsed=7.834s status=-1
error=Optional(Alamofire.AFError.sessionTaskFailed(error: Error Domain=NSURLErrorDomain Code=-1001 "The request timed out."
UserInfo={_kCFStreamErrorCodeKey=60, NSUnderlyingError=0x135e612f0 {Error Domain=kCFErrorDomainCFNetwork Code=-1001 "(null)"
UserInfo={_NSURLErrorNWPathKey=satisfied (Path is satisfied), viable, interface: en0[802.11], ipv4, dns, uses wifi, LQM: good,
_kCFStreamErrorCodeKey=60, _kCFStreamErrorDomainKey=1}},
), NSLocalizedDescription=The request timed out.,
NSErrorFailingURLKey=https://192.168.000.0/keepalive, _kCFStreamErrorDomainKey=1}))
KeepAlive FAIL ignored count=1 error=Server error : Optional(Alamofire.AFError.sessionTaskFailed(error: Error Domain=NSURLErrorDomain
Code=-1001 "The request timed out." UserInfo={_kCFStreamErrorCodeKey=60,
KeepAlive SEND id=A64AE4C0-28B4-41E3-AAC9-422C41D99D15 at=2026-02-24T12:22:58Z timeout=60.000000s
KeepAlive FAIL id=110B96DA-4D88-45E0-B8F7-D0A9798593AE elapsed=43.605s status=-1
error=Optional(Alamofire.AFError.sessionTaskFailed(error: Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost."
UserInfo={_kCFStreamErrorCodeKey=-4, NSUnderlyingError=0x135e60f60 {Error Domain=kCFErrorDomainCFNetwork Code=-1005 "(null)"
UserInfo={NSErrorPeerAddressKey=<CFData 0x144dfee40 [0x201746068]>{length = 16, capacity = 16, bytes =
0x100201bbc0a86f010000000000000000}, _kCFStreamErrorCodeKey=-4, _kCFStreamErrorDomainKey=4}},
), NSLocalizedDescription=The network connection was lost., NSErrorFailingURLStringKey=https://192.168.000.0/keepalive,
NSErrorFailingURLKey=https://192.168.000.0/keepalive, _kCFStreamErrorDomainKey=4}))
KeepAlive FAIL ignored count=2 error=Server error : Optional(Alamofire.AFError.sessionTaskFailed(error: Error Domain=NSURLErrorDomain
Code=-1005 "The network connection was lost." UserInfo={_kCFStreamErrorCodeKey=-4, NSUnderlyingError=0x135e60f60 {Error
Domain=kCFErrorDomainCFNetwork Code=-1005 "(null)" UserInfo={NSErrorPeerAddressKey=<CFData 0x144dfee40 [0x201746068]>{length = 16,
capacity = 16, bytes = 0x100201bbc0a86f010000000000000000}, _kCFStreamErrorCodeKey=-4, _kCFStreamErrorDomainKey=4}},
Network type changed, hasWiFiInterface :false
We are sending a keepalive request every 30 seconds to maintain the connection state with the device. Most of the issues occur during this keepalive process, and this is when the logs mentioned earlier are generated.
Based on our debugging so far, the keepalive function itself is being called as expected. However, the execution appears to stall while waiting for a response from the device. After remaining in that state for some time, the session eventually ends with either a timeout or a connection loss error.
We are use almofire 4.0.1.
According to the firmware developer, when this issue occurs, there are no corresponding values or logs received on the device side.
Therefore, we are currently investigating whether this might be related to a networking issue on the iPhone side.
All other features are functioning normally. The problem occurs only when downloading VOD video files, and the reproduction rate is 100% under that condition.
Dear Apple Carrier Relations / Engineering Team,
I am writing to you from MKSmart, a leading smart card and digital security solution provider.
We have successfully deployed our SM-DP+ (Subscription Management Data Preparation+) system, which is fully compliant with GSMA standards. Furthermore, MKSmart has officially achieved the GSMA SAS-SM (Security Accreditation Scheme for Subscription Management) certification.
Currently, we are facing technical difficulties when attempting to download eSIM profiles onto iPhone devices. The download process fails, and we believe our SM-DP+ server address (FQDN) or Root Certificates may not yet be whitelisted or recognized by Apple’s ecosystem.
To ensure a seamless experience for our customers on iOS devices, we would like to request your guidance on the following:
Onboarding Process: What are the formal steps for MKSmart to have our SM-DP+ server recognized and trusted by Apple devices?
Whitelisting: How can we submit our SM-DP+ FQDN and Root Certificates for Apple’s review and inclusion in the trusted list?
Carrier Bundle: Does MKSmart need to coordinate with specific carrier partners to update the Carrier Bundle, or is there a direct integration path for our infrastructure?
We have attached our GSMA SAS-SM certification and technical specifications for your reference. We are ready to provide any additional documentation or perform interoperability testing as required.
We look forward to your guidance and a successful collaboration.
Best regards,
Nguyen Do Khanh
Software Engineer
MKSmart Joint Stock Company
https:\mksmart.com.vn
Starting in iOS 26.4, PushKit has introduced a new "didReceiveIncomingVoIPPushWithPayload" delegate, making it explicit whether or not an app is required to report a call for any given push. The new delegate passes in a PKVoIPPushMetadata object which includes a "mustReport" property.
We have not documented the exact criteria that will cause a mustReport to return false, but those criteria currently include:
The app being in the foreground at the point the push is received.
The app being on an active call at the point the push is received.
The system determines that delivery delays have made the call old enough that it may no longer be viable.
When mustReport is false, apps should call the PushKit completion handler (as they previously have) but are otherwise not required to take any other action.
__
Kevin Elliott
DTS Engineer, CoreOS/Hardware
I've been able to run this sample project with the PIRServer. But the urls are still not blocked.
https://developer.apple.com/documentation/networkextension/filtering-traffic-by-url
https://github.com/apple/pir-service-example
I got this on the log
Received filter status change: <FilterStatus: 'running'>
I'm debugging an app I'm building and everything I'm seeing suggests I need to put in a request to Apple to turn on NetworkExtension → Packet Tunnel Provider entitlement for our Team ID and bundle IDs.
1: Is this true?
2: Doesn't the option in xcode handle this?
I'm building a HomeKit app that discovers Thread devices and visualizes the mesh topology. I can detect device roles (Router vs End Device via characteristic 0x0703) and identify Border Routers (via _meshcop._udp), but I cannot determine which Router is the parent of a given End Device. Any Thread device can act as a Router (a Nanoleaf bulb, an Eve plug, not just HomePods), and End Devices attach to these Routers as children. That parent-child relationship is what I'm trying to map, but there's no RLOC16, neighbor table, or parent identifier exposed through any available API.
I've tested every path I can find. Here's what I've tried on a network with 44 Thread devices and 6 Border Routers:
What works (partially)
HAP Thread Management Service (0x0701) gives me the device role from characteristic 0x0703, the OpenThread version from 0x0706, and node capabilities from 0x0702. That's the complete set of characteristics on that service. None of them contain RLOC16, parent Router, or neighbor data. This service also only exists on HAP-native Thread devices. My 20 Matter-over-Thread devices (Aqara, Eve Door, SmartWings, Onvis S4) don't have it at all.
MeshCoP Bonjour (_meshcop._udp) identifies Border Routers and the network name/Extended PAN ID. No topology data about other mesh nodes.
What doesn't work
ThreadNetwork framework (THClient) - retrieveAllCredentials() returns error Code 3 because the app can't access credentials stored by Apple Home. Even if it worked, THCredentials only contains network config (name, PAN ID, channel), not topology.
Direct CoAP queries - Border Routers don't route traffic from WiFi to Thread management ports. Mesh-local addresses aren't reachable. No Thread NWInterface in Network.framework.
Network.framework - No visibility into the Thread mesh from the WiFi side.
The only remaining path I can see (but it's not practical)
Matter cluster 0x0035 (Thread Network Diagnostics) appears to have exactly what I need: RLOC16, NeighborTable with isChild boolean, RouteTable. I haven't implemented this because it requires commissioning each device individually onto my app's own Matter fabric via Multi-Admin. That's 21 separate user-initiated pairing actions on my network. I can't ask end users to do that.
The core issue
Every Thread Router (whether it's a HomePod acting as a Border Router or a Nanoleaf bulb acting as a mesh Router) knows its own children and neighbors. The Border Routers also maintain route tables covering the mesh backbone. This data exists on the user's own devices but none of it is exposed to third-party apps.
Even something minimal would help. HMAccessory already exposes matterNodeID as a cross-protocol identifier. Exposing RLOC16 the same way would be enough, since parent-child relationships are encoded in the address itself (ParentRLOC = ChildRLOC & 0xFC00).
Has anyone found another approach I'm missing?
Thanks in advance for any pointers.
My team is developing an enterprise VPN application that needs to respond to Mobile Device Management (MDM) profile installations and removals in real-time. Our app uses the NetworkExtension framework and needs to update the UI immediately when VPN configurations are added or removed via MDM.
We are currently observing NEVPNConfigurationChangeNotification to detect VPN configuration changes:
While NEVPNConfigurationChangeNotification fires reliably when users manually remove VPN profiles through Settings > General > VPN & Device Management, it appears to have inconsistent behavior when MDM profiles containing VPN configurations are installed programmatically via MDM systems.
STEPS TO REPRODUCE
From MDM Admin Console: Deploy a new VPN profile to the test device
On Device: Wait for MDM profile installation (usually silent, no user interaction required)
Check Device Settings: Go to Settings > General > VPN & Device Management to confirm profile is installed
Return to App: Check if the UI shows the new VPN profile
Hello team,
I am trying to find out a way to block urls in the chrome browser if it is found in local blocked list cache. I found URL Filter Network very much suitable for my requirement. But I see at multiple places that this solution is only for Enterprise level or MDM or supervised device. So can I run this for normal user ? as my targeting audience would be bank users. One more thing how can I test this in development environment if we need supervised devices and do we need special entitlement ?
When trying to run sample project in the simulator then getting below error