Thanks, Matt! Please check FB9174140. My test servers are behind the VPNs. So I can not test your recommendation.

Hi Matt! Please let me know if I need to provide more information. Regards,

Thanks Matt! I uploaded sysdiagnose file to ticket.

Thanks, DTS! Yes, handleNewFlow method retutns false for "osinstallersetupd" process. Feedback Id: https://feedbackassistant.apple.com/feedback/9084810 Thanks

Thanks Matt! Your recommendation solved the issue. But I observed unexpected system restart too few times after setting the filter but could not get any system crash report. feedback id is 8912278. Regards,

Hi I already filed the bug FB8708473. Thanks

Thanks Matt! Please let me add few more details, below is my code. (void)configureDNSProxy {     ns_info(module, "DNS proxy configurations will be loaded");     [[NEDNSProxyManager sharedManager]      loadFromPreferencesWithCompletionHandler:^(NSError * __nullable loadError) {       if (loadError){         return;       }       NEDNSProxyProviderProtocol *tunnelProtocol = [[NEDNSProxyProviderProtocol alloc] init];       [tunnelProtocol setServerAddress:@"DNS Gateway"];       tunnelProtocol.providerBundleIdentifier = dnsProxyBundleID_;       [NEDNSProxyManager sharedManager].enabled = true;       [NEDNSProxyManager sharedManager].localizedDescription = @"DNS Proxy";       [NEDNSProxyManager sharedManager].providerProtocol = tunnelProtocol;       [[NEDNSProxyManager sharedManager] saveToPreferencesWithCompletionHandler:^(NSError * _Nullable savePrefError) {         if (savePrefError) {           return;         }       }];     }]; } (OSSystemExtensionReplacementAction)request:(OSSystemExtensionRequest *)request 																		actionForReplacingExtension:(OSSystemExtensionProperties *)existing 																withExtension:(OSSystemExtensionProperties *)ext { 		return OSSystemExtensionReplacementActionReplace; } (void)requestNeedsUserApproval:(OSSystemExtensionRequest *)request { } (void)request:(OSSystemExtensionRequest *)request didFailWithError:(NSError *)error { } (void)request:(OSSystemExtensionRequest *)request didFinishWithResult:(OSSystemExtensionRequestResult)result {   [self configureDNSProxy]; } (void) initializeDNSProxy { 				NSString *extensionIdentifier = dnsProxyBundleID_; 				dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);				 OSSystemExtensionRequest *req = [OSSystemExtensionRequest activationRequestForExtension:extensionIdentifier 																																													queue:queue]; 				req.delegate = self; 				[[OSSystemExtensionManager sharedManager] submitRequest:req]; } It is called [myobj initializeDNSProxy]; Is it correct code? Thanks

Same reply was posted twice inadvertently, therefore removed it.

Thanks Matt and Eskimo! Your suggestion helped me a lot.

Thanks Matt! int main(int argc, char *argv[]) {   @autoreleasepool {     [NEProvider startSystemExtensionMode];   }       dispatch_main(); } Does RunLoop work with dispatch_main()? Anyway, SCNetworkReachabilitySetDispatchQueue works for me. Thanks

Thanks for your reply!But Acitivety Monitor shows different Process id for each extension. Is it correct? Regards,Anand Choubey

Thanks Matt!Try using a different DNS server and see if you start getting traffic there...Sorry, I did not get your suggestion. How to use different DNS server in getaddrinfo?We do not have any access policy on machine. Or do I miss your point?I missed one strange point before:If Network extension is disconnected from Network Preferences, all the block calls returns with resolved IP address.Regards,

Thanks Matt!It is not intemittent. dns resolution is never received.If matchDomainsNoSearch is set to YES.getaddrinfo throws error:error in getaddrinfo: nodename nor servname provided, or not knownAny recommendation to solve this issue?Regards,Anand Choubey

Sorry, I missed question:Could you please confirm whether behaviour change this is bug in 10.15.5?Thanks

Thanks EskimoTwo Network extension enablment flows were triggered at same time that leads to the crash. Now I fixed it.Regards,Anand Choubey