We are building a macOS client where we make a web socket connection to our server using NWConnection. The code to to create NWParameters is: let options = NWProtocolTLS.Options() let securityProtocolOptions = options.securityProtocolOptions //....configure security options for server and client cert validation... let parameters = NWParameters(tls: options) let wsOptions = NWProtocolWebSocket.Options() wsOptions.autoReplyPing = true wsOptions.setAdditionalHeaders(additionalHeaders.map { ($0.key, $0.value) } ) parameters.defaultProtocolStack.applicationProtocols.insert(options, at: 0) With these parameters and an NWEndpoint object, we create a connection which connects and transfers data well from both sides. However, whenever server gracefully closes the connection, the client remains oblivious to this and does not close the connection. It only detects a timeout when trying to send some data over the connection after the server disconnect. We looked into Wireshark and we do not see any FIN,ACK or RST packets being received from server. However, in our windows client, when same exact server closes the connection, we are seeing FIN, ACK and connection immediately closes on client side as well. We also tried to test same behaviour in golang with a small snippet created by our team member running on Mac itself. This snippet also receives FIN,ACK from server and closes the connection immediately. Only NWConnection in our Mac client does not receive close connection. So, the question arises, why is NWConnection not receiving FIN,ACK and not closing the connection when a windows as well as a golang client on Mac is able to. Is there any extra configuration required for NWConnection or NWParameter? Is the NWParameter creation code correct? We already checked and we are continuously calling receiveMessage on the NWConnection object. So, missing read is not the issue here. Also, I do not see any connection timeout option in NWProtocolWebSocket but it exists in NWProtocolTCP. So, is there a way to set connection timeout for web socket connection using NWConnection?

We are developing a PacketTunnel provider based System Extension that creates a utun device when tunnel settings are supplied and everything works fine. Now, when we try to bring down the utun created by our extension using ifconfig utun down, the extension does not receive packets anymore. So the first question is, is there a way for extension to know that its been marked down? We would want to display a status to our UI to users in case they forget about it. Next is, when we mark the utun device up next using ifconfig utun up, it still does not receive any packets. It stays down. The only way to start reading the packets is to start the tunnel again where we re-supply the tunnel settings. Is this expected behaviour? Is there anything missing here?