Hi Matt! Thanks for the hints and suggestions! I made the suggested changes as below: override func startTunnel(   options: [String: NSObject]?, completionHandler: @escaping (Error?) - Void  ) { NSLog("Tunnel started")   remoteEndpoint = NWHostEndpoint(hostname: "192.168.0.27", port: "62165") let settings = NEPacketTunnelNetworkSettings(tunnelRemoteAddress: "192.168.0.27") setTunnelNetworkSettings(settings) { [weak self] (error) in     NSLog("Did finish setting network: \(error)")     completionHandler(error)     self?.readPackets()   } } The the log on the app side is: Launched manager is enabled: true connecting... connected connection did send, data: {length = 11, bytes = 0x68656c6c6f20776f726c64} connection did send, data: {length = 11, bytes = 0x68656c6c6f20776f726c64} connection did send, data: {length = 11, bytes = 0x68656c6c6f20776f726c64} The log on the packet tunnel provider side is: default 09:54:14.886492-0800 kernel memorystatus: set assertion priority(3) target VPNTestAppExtension:2490 default 09:54:14.915952-0800 VPNTestAppExtension Hello, I'm launching as euid = 501, uid = 501, personaid = 1000, type = DEFAULT, name = private default 09:54:14.935892-0800 VPNTestAppExtension Initializing connection default 09:54:14.935951-0800 VPNTestAppExtension Removing all cached process handles default 09:54:14.936009-0800 VPNTestAppExtension Sending handshake request attempt #1 to server default 09:54:14.936120-0800 VPNTestAppExtension Creating connection to com.apple.runningboard default 09:54:14.938035-0800 VPNTestAppExtension Handshake succeeded default 09:54:14.938097-0800 VPNTestAppExtension Identity resolved as xpcservicecom.test.test.extension([daemoncom.apple.neagent-ios:313:313]) default 09:54:14.938528-0800 VPNTestAppExtension Bootstrapping; Bootstrap complete. Ready for handshake from host. default 09:54:14.939788-0800 VPNTestAppExtension [u C4AA1961-9F06-4C18-BD46-BBA24C2EDC14] [(null)((null))] Prepare received as euid = 501, uid = 501, personaid = 1000, type = DEFAULT, name = private default 09:54:14.942125-0800 VPNTestAppExtension [u 9B875CFD-574F-4F52-8EB0-B9004E7FA876] [private(private)] Set sole personality. default 09:54:14.947329-0800 VPNTestAppExtension [u 9B875CFD-574F-4F52-8EB0-B9004E7FA876] [private(private)] Begin using received as euid = 501, uid = 501, personaid = 1000, type = DEFAULT, name = private default 09:54:14.950351-0800 kernel memorystatus: set assertion priority(14) target VPNTestAppExtension:2490 default 09:54:14.956485-0800 VPNTestAppExtension networkd_settings_read_from_file initialized networkd settings by reading plist directly default 09:54:14.956536-0800 VPNTestAppExtension networkd_settings_read_from_file initialized networkd settings by reading plist directly default 09:54:14.957400-0800 VPNTestAppExtension nw_path_evaluator_start [71AC9ED0-F79D-4CA6-BA18-C06BBD3A6746 NULL generic, indefinite] path: satisfied (Path is satisfied), interface: en0, ipv4, ipv6, dns default 09:54:14.973144-0800 VPNTestAppExtension [Extension com.test.test.extension]: Calling startTunnelWithOptions with options 0x102d0dd70 default 09:54:14.973443-0800 VPNTestAppExtension Tunnel started default 09:54:14.974246-0800 VPNTestAppExtension [Extension com.test.test.extenison]: provider set tunnel configuration to tunnelRemoteAddress = 12-char-str default 09:54:14.997253-0800 VPNTestAppExtension Did finish setting network: nil default 09:54:14.997659-0800 VPNTestAppExtension Did try reading packets using packFlow: Optional(NEPacketTunnelFlow: 0x102c09c00) Looks like I did successful NEPacketTunnelNetworkSettings as it prints error as nil. However, I still cannot getting packets using the NEPacketTunnelFlow: 0x102c09c00. Any other things should I do?