How to keep device connected to lan but block its access to the cloud/web
I have an inverter and I managed to read its data into my smart home system using the modbus protocol. Now I want to keep being able to read its data, so keeping it connected to the lan and accessible by other devices, but block it from accessing the web/internet, so that the data is not sent to the cloud (as a matter of privacy).
From all that I could read my router seems to only be able to totally block the access of a device to the internet AND LAN via the advanced -> security -> access control tab. I would also say that the modbus query is on port 502 of the inverter. Any help in the form of a step-by-step solution is greatly appreciated