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.

Getting cannot parse response on all downalod tasks. Example output "BackgroundDownloadTask <E277D3D6-2FF0-4574-A617-1612ED779151>.<1>", "LocalDownloadTask <E277D3D6-2FF0-4574-A617-1612ED779151>.<1>" ), NSLocalizedDescription=cannot parse response, _kCFStreamErrorDomainKey=4, NSErrorFailingURLStringKey=https://traffic.megaphone.fm/ESP7536701051.mp3?updated=1740573440, NSErrorFailingURLKey=https://traffic.megaphone.fm/ESP7536701051.mp3?updated=1740573440} Can't seem to find a workaround that i can push for app to work with 18.4 beta. Can't believe that beta went to the public.

Apple multi-peer with 12 devices is unstable. Dear All, Has anyone tried Apple multi-peer with 12 devices connected? We are building an application relying on multi-peer where 12 Ipads will be updating data and each device needs to share data between. Can anyone tell me if we can use multi-peer framework for connecting 12 devices in the multi-peer network? We are facing stability problems in the connection when we connect 12 devices in the network.

HI, I am currently prototyping an app that compares transport protocol performances using a peer to peer connection. I have already setup TCP and UDP connections and am sending data between the clients, it works like I want it to. Next I was trying to setup a connection using QUIC, but the NWConnection.State stays in the preparing state and I couldn't find a way to get more information from the framework or the instances about why it was not fully connecting. After searching the internet and stumbling across the forum I noticed that the missing encryption might be the issue, so I created a local root certificate*. Then I used the SecPKCS12Import function to read/extract the SecIdentity instance of the p12 file (cert + private key) stored in my bundle** and set it as a local identity with the sec_protocol_options_set_local_identity function***. //function that creates/returns different NWParameteres //... let quicOptions = NWProtocolQUIC.Options() quicOptions.alpn = ["test"] if let identityPath = Bundle.main.path(forResource: "QUICConnect", ofType: "p12"), let identityData = try? Data(contentsOf: URL(fileURLWithPath: identityPath)) { if let identity = loadIdentityFromPKCS12(p12Path: identityPath, password: "insecure") { //**** sec_protocol_options_set_local_identity(quicOptions.securityProtocolOptions, sec_identity_create(identity)!) } } let parameters = NWParameters(quic: quicOptions) parameters.includePeerToPeer = true return parameter The documentation comments had me thinking that setting a local identity could be enough, since it consists of the private key for the "server" and the cert for the "client". Set the local identity to be used for this protocol instance. Unfortunately at this stage the QUIC Connection is still stuck in preparing state and since I don't know how to extract more information from the networking connection instances/framework, I am stuck. I have seen the following other functions in Quinns answer and am confident that I could somehow figure it out with some more time put into it, but not really understanding why or how I could do it better in the future. So I am also wondering how I could have found info about this more efficiently and tackled this more strategically without needing to browse through so many forums. sec_protocol_options_set_verify_block sec_protocol_options_set_challenge_block I would really appreciate any help, many thanks. BR Matthias! TLDR: I want to establish a peer to peer QUIC Connection but the state is stuck in preparing. Secondary question is how I could approach a similar topic more efficiently next time, instead of browsing many forums. * I had to create it with the openssl CLI since the keychain app created a cert, that when using the openssl CLI to get the info would throw an error unless used with the -legacy flag. The root cert, created form the keychain app also wasn't able to be imported by the SecPKCS12Import function. No clue why but it worked with a cert created from the openssl CLI. There's a chance that I messed up something else here, but these were my experiences. Info: Since QUIC is limited to TLS v1.3 I can't use PSK, afaik. Therefore the TicTacToe doesn't help me anymore. ** I know this is highly insecure, I am just using it for prototyping. *** Forum users Info: One needs to use the sec_identity_create function to convert the SecIdentity instance to the expected parameter type. **** func loadIdentityFromPKCS12(p12Path: String, password: String) -> SecIdentity? { guard let p12Data = try? Data(contentsOf: URL(fileURLWithPath: p12Path)) else { print("didnt find p12 file at path") return nil } let options: NSDictionary = [kSecImportExportPassphrase as String: password, kSecImportToMemoryOnly as String: kCFBooleanTrue!] var items: CFArray? let status = SecPKCS12Import(p12Data as CFData, options, &items) if status == 0, let dict = (items as? [[String: Any]])?.first { if let identity = dict[kSecImportItemIdentity as String] { return identity as! SecIdentity } else { return nil } } else { return nil } } PS: For TCP and UDP I am using bonjour to discover the peer and connect to the advertised ports. AFAIK I can't just use _testproto._quic to advertise a QUIC service like with tcp and udp. Therefore I am using the local domain name (it's just for prototyping and always the same device) and a hard coded port number to create the peer connection. When using a wrong name the DNS threw an error telling it could not find a peer, so the lookup itself is working I guess. The lookup should come from the cache since I already looked up when connecting to the same peer via Bonjour. //Server //.... listener = try NWListener( using: transportProtocol.parameters, on: Config.quicPort ) //... listener.newConnectionHandler = { [weak self] connection in self?.connection?.cancel() self?.connection = nil self?.connection = C(connection) //here C is a generic that conforms to a custom connection interface, nothing to worry about :) self?.connectionStatus.value = "Connection established" } listener.stateUpdateHandler = { [weak self] state in self?.connectionStatus.value = "\(state)" } listener.start(queue: .global()) //Client //... nwConnection = NWConnection(host: "iPad.local.", port: Config.quicPort, using: transportProtocol.parameters) //...

Hi, I've noticed a weird behavior happening on Sequoia with DF bit: On machine where SIP is disabled, when I do /sbin/ping -D -s 1400 8.8.8.8 I do see the DF bit in wireshark On machine where SIP is enabled, when I do /sbin/ping -D -s 1400 8.8.8.8 I do not see the DF bit in wireshark The -D flag should set the DF bit but for some reason it doesn’t if the SIP is enabled. Perhaps there was any change in permission/entitlements mechanism in Sequoia that can explain it ? I'm using the built-in ping command so maybe it should be signed with more entitlements ?

I am trying to commission an ESP32-H2 Matter device using the chip-tool. It's running the Light Switch sample. I can commissioning it using the iOS Home App, so I know the code on it's working okay. I would like to understand more about the Fabric process, so I'd like to use the Home Pod powered Thread network rather than setting up an instance of Open Thread Border Router. I have created a simple iOS app and can fetch the activeOperationalDataSet from the Preferred network using func obtainPreferredNetworkCredentials() async -> (Void) { let client = THClient() let bIsPreferredAvailable = await client.isPreferredAvailable() if bIsPreferredAvailable == true { var credential: THCredentials? do { credential = try await client.preferredCredentials() if let dataset = credential?.activeOperationalDataSet { print(dataset.hexDescription) } } catch { print("Failed to get the credentials") } } } The hexDescription comes from this extension extension Data { var hexDescription: String { return reduce("") {$0 + String(format: "%02x", $1)} } } I am decoding the Data and displaying it as a hex string. It looks something like this: 0e080000000000000000000300001935060004001fffc002089f651677026f48070708fd9f65167702000ee90914b5d1097de9bb0818dc94690c0402a0f7f8 However, when I attempt to commission the device, it fails during ThreadSetup. Googling the issue says most likely the Operational Dataset is wrong in some way. Before I spend too much time on this, I want to make sure I'm doing the right thing in terms of getting the Operational Dataset to use with the chip-tool. Any help is appreciated!

For years our iOS apps have experienced a networking problem, which blocks them connecting to our servers via their API endpoint domains. How can we recover after the scenario described below? Using 3rd party error logging solutions, which have different endpoint domains, we can record the error: NSUnderlyingError": Error Domain=kCFErrorDomainCFNetwork Code=-1200 "(null)" UserInfo={_kCFStreamPropertySSLClientCertificateState=0, _kCFNetworkCFStreamSSLErrorOriginalValue=-9816, _kCFStreamErrorDomainKey=3, _kCFStreamErrorCodeKey=-9816, _NSURLErrorNWPathKey=satisfied (Path is satisfied), viable, interface: pdp_ip0[lte], ipv4, dns, expensive, uses cell}, "_NSURLErrorFailingURLSessionTaskErrorKey": LocalDataTask <DEDBFA4D-810D-4438-A6A0-95E3B9668B9E>.<308>, "_kCFStreamErrorDomainKey": 3, "_NSURLErrorRelatedURLSessionTaskErrorKey": <__NSSingleObjectArrayI 0x301f82e60>( LocalDataTask <DEDBFA4D-810D-4438-A6A0-95E3B9668B9E>.<308> ) "NSLocalizedDescription": An SSL error has occurred and a secure connection to the server cannot be made., "NSLocalizedRecoverySuggestion": Would you like to connect to the server anyway? -9816 is the "server closed session with no notification" error based on comments in CoreFoundation source files. Subsequent API endpoint calls to the same domain return the same error. The SSL error occurs most prevalently after a server outage. However, despite our best efforts, we have been unable to replicate triggering the problem for development purposes via experiments with our server. When the error occurs the users report that: Fully closing (i.e. not just sending to background) and reopening the app does NOT clear connectivity to our server being blocked. Problem seems more prevalent when using mobile/cell data. Switching from mobile/cell data to WIFI resolves the connection problem and then switching back to mobile/cell data shows the problem again. So the underlying problem is not cleared. All other apps on the same device and mobile/cell data or WIFI connection, like Safari, have no problems connecting to the Internet. Deleting and reinstalling, or updating (when an update is available) resolves the problem. Or after waiting a few days the problem seems to resolve itself. The last two point above suggest that something is persisted/cached in the app preventing it from connecting properly with subsequent network attempts. Notes: We have one shared instance of the URLSession in the app for its networking because we are aware of the perils of multiple URLSession instances. We recently added conditions to call the URLSession await reset() method when detecting the SLL errors before repeating the request. It is debatable whether this reduces the problem as we still see logged cases with the subsequent requests hitting the same -9816 error. URLSession configuration: let config = URLSessionConfiguration.default config.timeoutIntervalForResource = 22 config.timeoutIntervalForRequest = 20 config.requestCachePolicy = .reloadIgnoringLocalCacheData config.urlCache = nil

I have an NEPacketTunnelProvider that's configured using NEPacketTunnelNetworkSettings. I'm using NEDNSSettings to configure the DNS resolver of the packet tunnel, and would like to specify the exact domains that should use this resolver using the matchDomains member variable. While it's not explicitly mentioned in the documentation [1], I've noticed that if a domain is present in matchDomains, then all subdomains of it will also be resolved using this resolver, as if a wildcard match rule is in place. I wanted to ask if this the intended behavior, and if so, is there any way to disable it so that only exact domain matches will be resolved? I.e., if "example.com" is in the matchDomains list, I would like requests for this domain be resolved using the configured DNS resolver, while ignoring requests to the subdomain"test.example.com". [1] https://developer.apple.com/documentation/networkextension/nednssettings/matchdomains

I am trying to connect an iPhone 16 (iOS 18.3) to a Wi-Fi device with the SSID "DIRECT-DR_6930_KP201128", but every time, without being able to enter the Wi-Fi password, the message "Unable to join the network 'DIRECT-DR_6930_KP201128'" is displayed. Below are the system logs from the connection failure. Could you please tell me the cause of the connection failure? By the way, an iPhone SE 2nd (iOS 18.2.1) can connect to the same Wi-Fi device without any issues. System Logs: ・Jan 31 19:18:14 900-iPhone-16-docomo Preferences(WiFiKit)[351] : {ASSOC-} association finished for DIRECT-DR_6930_KP201128 - success 0 ・Jan 31 19:18:14 900-iPhone-16-docomo runningboardd(RunningBoard)[33] : Assertion 33-351-4412 (target:[app<com.apple.Preferences(DE1AB487-615D-473C-A8D6-EAEF07337B18)>:351]) will be created as inactive as start-time-defining assertions exist ・Jan 31 19:18:14 900-iPhone-16-docomo Preferences(WiFiKit)[351] : association failure: (error Error Domain=com.apple.wifikit.error Code=12 "Unknown Error" UserInfo={NSDebugDescription=Unknown Error, NSUnderlyingError=0x303307660 {Error　Domain=com.apple.corewifi.error.wifid Code=-3938 "(null)"}}) ・Jan 31 19:18:14 900-iPhone-16-docomo Preferences(WiFiKit)[351] : dismissing credentials view controller for DIRECT-DR_6930_KP201128

Hello. I'm developing on a cross-platform app to help user connect enterprise network and found it difficult in macOS. The issue is, I guided user to install profile, but the authentication won't start immediately even the cable is plugged in or the WLAN is connected. There is still some manual operation to be done: Ethernet: Select the correct profile, and click the Connect button. Wlan: Click the Connect button. (The profile contains SSID so need't select the correct profile) Obviously, the operation is still not easy for users to understand and follow. So, is there any method to auto connect 802.1x network using the selected profile in terminal or by code? I mean, the manual operation is not necessary, maybe you can tell me a better solution. BTW, I found it possible to connect WLAN and auto select the correct profile by using this command networksetup -setairportnetwork en1 MY_SSID, but it could be very slow since the authentication seemed start 30 sec after connecting the SSID. So I believe it not the best solution.

We found there is a significant crash reports (most of them are from iOS 17, the rest are iOS 16 and 15) comes from network loader from CFNetwork. Apparently it seems there are two types of crashes if we checked from the stack trace, the one we found from both Xcode organizer and 3rd party crash reporter is referring to URLConnectionLoader::loadWithWhatToDo and the other one from our 3rd party crash reporter (didn’t found the report from Xcode organizer) referring to _CFURLResponseCreateFromArchiveList (this one only happened on iOS 17.5 and later devices). It seems that they are both kinda similar which might point to the same root cause. From what I’ve seen, we never touch the lower level API directly, we usually use the URLSession to manage our API request. The crashed stack trace also didn’t give any indication about which of our app code that triggered the crash, it only shows calls to Apple’s internal SDKs so we are unsure how to approach this issue meanwhile the crash event already reached 800+ in the last 30 days. Unfortunately, we cannot reproduce the issue as the stack trace itself seems unclear to us. I have submitted a report through feedback assistant with number: FB14679252. Would appreciate if anyone can give any advice on what we can do to avoid this in the future and probably any hint on why it could happened. Hereby I attached the crash reports that we found each from Xcode crash report and our 3rd party crash reporter (the report said it crashed on com.apple.CFNetwork.LoaderQ) so you could get a glimpse of the similarity. Xcode crash report xcode crash report.crash 3rd party crash report 3rd party crash report.txt

Our app receives real-time GPS and aircraft data from devices via UDP broadcast and/or multicast on a WiFi network created by the device. We have identified that the iPhone or iPad will just stop receiving UDP broadcast/multicast data for an interval of time. In general, it appears after roughly every 128KB of data is received. In the attached screenshot from Xcode instruments, you can see the data reception alternating on/off. We have verified with Wireshark that the data is still flowing during that entire time period. And by tracking bytes received the app ultimately receives about 55% of the bytes, which tracks with the Network graph. We have used different approaches to the network code, including GCDAsyncUdpSocket, BSD Sockets, and the Network framework. We've tried it on background threads and the main thread. Tested it on iPads and iPhones. All produce the same result. The data is just never reaching the app code. Any insight on what may be temporarily disabling data reception?

When our content filter is deployed, some customers report issues which show that the content filter activation was performed but the filter is showing the state [activated waiting for user]. This typically happens if the customer isn't deploying a profile to pre-authorise the system extension. The customers report that there was no popup shown for them to allow the filter to complete activation. Once the filter is in this state, there doesn't seem to be a way to clear it without resorting to disabling SIP. Attempting a deactivation does not work, the filter remains in the same state. Is there a way we can we resolve this "stuck" state when it happens without disabling SIP?

Using NEHotspotConfigurationManager.joinAccessoryHotspot(_ accessory: ASAccessory, passphrase: String) to connect the WiFi, but this function implicitly sets joinOnce to YES. Is there any api that can use ASAccessory to connect to WiFi while maintaining JoinOnce = false. Is it possible to open up this feature？

I'm working on two Swift applications which are using QUIC in Network.framework for communication, one serve as the listener (server) and the other serve as the client so that they can exchange data, both the server and the client app are running under the same LAN, the problem I met is that when client try to connect to the server, the connection will fail due to boring SSL, couple questions: Since both the server app and client app are running under the same LAN, do they need TLS certificate? If it does, will self-signed certificate P12 work? I might distribute the app in App Store or in signed/notarized dmg or pkg to our users. If I need a public certificate and self signed wouldn't work, since they are just pair of apps w/o fixed dns domain etc, Is there any public certificate only for standalone application, not for the fixed web domain?

I would like to test running some Thread Networking code on my MacOS machine: import ThreadNetwork let client = THClient() let bIsPreferredAvailable = await client.isPreferredAvailable() but I get some errors when trying to create an instance of the THClient class: Client: -[THClient connectToXPCService]_block_invoke - CTCS XPC Client is interrupted. Client: -[THClient getConnectionEntitlementValidity]_block_invoke - clientProxyWithErrorHandler Error: Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named com.apple.ThreadNetwork.xpc" UserInfo={NSDebugDescription=connection to service named com.apple.ThreadNetwork.xpc} Client: -[THClient init] - XPC Client Init Failed Invalidating XPC connection. Client: -[THClient getConnectionEntitlementValidity]_block_invoke - clientProxyWithErrorHandler Error: Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named com.apple.ThreadNetwork.xpc" UserInfo={NSDebugDescription=connection to service named com.apple.ThreadNetwork.xpc} How can I get the code to run?

CFNetwork None CFURLResponseGetRecommendedCachePolicy None 0 CFNetwork None CFHTTPCookieStorageUnscheduleFromRunLoop None 0 CFNetwork None /_/_CFNetworkAgentMessageProcessorMain None 0 CFNetwork None CFURLDownloadCancel None 0 CFNetwork None CFURLDownloadCancel None 0 libdispatch.dylib None /_dispatch/_block/_async/_invoke2 None We've observed intermittent crashes in our production environment, exclusively affecting customers running macOS 10.15 and 11. The crash logs consistently show a stack trace involving CFHTTPCookieStorageUnscheduleFromRunLoop and CFURLDownloadCancel within the CFNetwork framework. This suggests potential issues with cookie storage management and/or URL download cancellation. Could the team please analyze these crash logs and provide insights into: The root cause of the crashes. Potential race conditions or synchronization issues. Recommendations for mitigating or resolving the problem. Your assistance in resolving this issue is greatly appreciated."

I use eapolcfg in Apple's open source eap8021x repository to connect to the enterprise network. 1.https://github.com/gfleury/eap8021x-debug https://opensource.apple.com/source/eap8021x/eap8021x-304.100.1/ Our enterprise network authentication is PEAP. So far, I have created a profile using the following commands and have done the access. ./eapolcfg createProfile --authType PEAP --SSID myssid --securityType WPA2 --userDefinedName MyProfile ./eapolcfg setPasswordItem --password mypassword --name myname --SSID myssid ./eapolcfg startAuthentication --interface en0 --SSID myssid After I performed this series of operations, I passed BOOL success = [self.interface associateToEnterpriseNetwork:network identity:nil username:username password:password error:&amp;error]; Connection will pop up the following pop-up window, sometimes associateToEnterpriseNetwork will fail. I don't know what went wrong, is it that I missed some steps through the eapolcfg [tool?] This function also reports the following error：Error Domain=com.apple.coreWLAN.EAPOL.error Code=1 "(null)" Please answer my questions. Thank you very much

I am looking for inputs to better understand MacOS entitlements. I ask this in context of OpenJDK project, which builds and ships the JDK. The build process makes uses of make tool and thus doesn't involving building through the XCode product. The JDK itself is a Java language platform providing applications a set of standard APIs. The implementation of these standard APIs internally involves calling platform specific native library functions. In this discussion, I would like to focus on the networking functions that the implementation uses. Almost all of these networking functions and syscalls that the internal implementation uses are BSD socket related. Imagine calls to socket(), connect(), getsockopt(), setsockopt(), getaddrinfo(), sendto(), listen(), accept() and several such. The JDK that's built through make is then packaged and made available for installation. The packaging itself varies, but for this discussion, I'll focus on the .tar.gz archived packaging. Within this archive there are several executables (for example: java, javac and others) and several libraries. My understanding, based on what I have read of MacOS entitlements is that, the entitlements are set on the executable and any libraries that would be loaded and used by that executable will be evaluated against the entitlements of the executable (please correct me if I misunderstand). Reading through the list of entitlements noted here https://developer.apple.com/documentation/bundleresources/entitlements, the relevant entitlements that an executable (like "java") which internally invokes BSD socket related syscalls and library functions, appear to be: com.apple.security.network.client - https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.security.network.client com.apple.security.network.server - https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.security.network.server com.apple.developer.networking.multicast - https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.developer.networking.multicast Is my understanding correct that these are the relevant ones for MacOS? Are there any more entitlements that are of interest? Would it then mean that the executables (java for example) would have to enroll for these entitlements to be allowed to invoke those functions at runtime? Reading through https://developer.apple.com/documentation/bundleresources/entitlements, I believe that even when an executable is configured with these entitlements, when the application is running if that executable makes use of any operations for which it has an entitlement, the user is still prompted (through a UI notification) whether or not to allow the operation. Did I understand it right? The part that isn't clear from that documentation is, if the executable hasn't been configured with a relevant entitlement, what happens when the executable invokes on such operation. Will the user see a UI notification asking permission to allow the operation (just like if an entitlement was configured)? Or does that operation just fail in some behind the scenes way? Coming back to the networking specific entitlements, I found a couple of places in the MacOS documentation where it is claimed that the com.apple.developer.networking.multicast entitlement is only applicable on iOS. In fact, the entitlement definition page for it https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.developer.networking.multicast says: "Your app must have this entitlement to send or receive IP multicast or broadcast on iOS. It also allows your app to browse and advertise arbitrary Bonjour service types." Yet, that same page, a few lines above, shows "macOS 10.0+". So, is com.apple.developer.networking.multicast entitlement necessary for an executable running on MacOS which deals with multicasting using BSD sockets? As a more general comment about the documentation, I see that the main entitlements page here https://developer.apple.com/documentation/bundleresources/entitlements categorizes some of these entitlements under specific categories, for example, notice how some entitlements are categorized under "App Clips". I think it would be useful if there was a category for "BSD sockets" and under that it would list all relevant entitlements that are applicable, even if it means repeating the entitlement names across different categories. I think that will make it easier to identify the relevant entitlements. Finally, more as a long term question, how does one watch or keep track of these required entitlements for these operations. What I mean is, is it expected that application developers keep visiting the macos documentation, like these pages, to know that a new entitlement is now required in a new macos (update) release? Or are there other ways to keep track of it? For example, if a newer macos requires a new entitlement, then when (an already built) executable is run on that version of macos, perhaps generate a notification or some kind of explicit error which makes it clear what entitlement is missing? I have read through https://developer.apple.com/documentation/bundleresources/diagnosing-issues-with-entitlements but that page focuses on identifying such issues when a executable is being built and doesn't explain the case where an executable has already been shipped with X entitlements and a new Y entitlement is now required to run on a newer version of macos.

I'm facing an issue where if a WiFi network is turned off and back on within a short time frame (2-4 seconds), iOS still shows the device as connected but does not send a new DHCP request. This causes a problem for my network device, which relies on the DHCP request to assign an IP address. Without the request, the device is unable to establish a socket connection properly. Is there any way to force iOS to send a DHCP request immediately when reconnecting to the network in this scenario? Are there any known workarounds or configurations that might help ensure the DHCP process is re-triggered? Any insights would be appreciated. Thanks!

Dear Apple： We found that after mirroring an iPhone and a Mac, calling the NEHotspotConfigurationManager applyConfiguration interface on the iPhone fails to connect to Wi-Fi. Are there any restrictions on using this interface in mirror mode?