ng-socket | Angular Module for Socket.io | Socket library

Normally the ionic serve command use the app name as app, so that might be the problem.

Under the hood that command runs ng run app:serve --host=localhost --port=8100, so you can try to map it into the package.json as a custom script with your app name.

AES is only about encryption with a fixed key, not about key management. Based on your example it looks like you actually want to protect the socket based communication between two parties. Please use TLS for this - it is an well established protocol for this purpose (base for HTTPS) which cares about authentication, encryption, key management, ...

It is strongly recommended to use such established solutions instead of building your own, since the latter is easily to get wrong. For example the thread you reference is using AES in plain CBC mode which does not provide any integrity. This means a man in the middle attacker can change the encrypted data without the communication peers being able to detect such modification. TLS cares about all of this properly by default.

Some parts of your question have been asked before.

Establishing an IPv6 connection using sockets in python

However, it is not the entire reason why it is not working correctly. If you look at your IPv6 address. fe80::cbdd:d3da:5194:99be%eth1 You can see the %eth1 at the end. That is not part of the internet address. Change HOST to HOST = 'fe80::cbdd:d3da:5194:99be'. And it should work.

I would also like to point out another error in your code. You are attempting to send a string (received from input) over the socket. However, this method only accepts byte like objects. You can add data = data.encode('utf-8') to fix this.

Probably the socket.io-client protocol version (EIO) from ng-socket-io package is outdated in relation to socket.io protocol version in your server.

You're passing the address of a struct sockaddr_in to the inet_ntop function. For an AF_INET socket it expects a pointer to a struct in_addr.

So instead of this:

The while loop condition will run one more time than there are zombie child processes that need to be waited for. So if you use wait() instead of waitpid() with the WNOHANG flag, it'll potentially block forever if you have another still running child - as wait() only returns early with an ECHLD error if there are no child processes at all. A robust generic handler will use waitpid() to avoid that.

Picture a case where the parent process starts multiple children to do various things, and periodically sends them instructions about what to do. When the first one exits, using wait() in a loop in the SIGCHLD handler will cause it to block forever while the other child processes are hanging around waiting for more instructions that they'll never receive.

Or, say, an inetd server that listens for network connections and forks off a new process to handle each one. Some services finish quickly, some can run for hours or days. If it uses a signal handler to catch exiting children, it won't be able to do anything else until the long-lived one exits if you use wait() in a loop once that handler is triggered by a short-lived service process exiting.

Ok.. just try to learn code from here -> https://github.com/doug-leith/appFirewall

Thanks dude for providing minus feedback for me. But my answer is the only one on internet which lead to working firewall!

After encountering the EXACT same issue when using the WebSocket object in the browser, I dug deeper and found this in the documentation of the Google Load Balancer service we're using:

The timeout for a WebSocket connection depends on the configurable backend service timeout of the load balancer, which is 30 seconds by default. This timeout applies to WebSocket connections regardless of whether they are in use. For more information about the backend service timeout and how to configure it, see Timeouts and retries.

https://cloud.google.com/load-balancing/docs/https?fbclid=IwAR2Qugtlyvd05VteGWk2RCevebUJrHTHyW9RHAwYiPxudM6qOovaa2Zdqpk

Check this article for more info about how to config your Load Balancer to correctly handle WebSockets:

https://medium.com/johnjjung/how-to-use-gcp-loadbalancer-with-websockets-on-kubernetes-using-services-ingresses-and-backend-16a5565e4702

Your txData struct fields are not exported means they are not visible outside of your package because they start with a lowercase letter. So encoding/json package can't access them. Capitalize the first letter of the fields to make them exported.