I am setting up a firewall on my Volumio Raspberry Pi and was wondering which ports need to be opened for it to work. When I run sudo netstat -4lnp, that are about 26 services listening across 19 tcp and udp ports. Some are obvious (SSH, SMB, DHCP, NTP, DNS) but what others need to be opened? I set up a firewall and allowed all 19 ports (see attached screenshot), and neither the web browser nor the Volumio app were able to connect. I would like to be able to turn on the firewall as a measure towards securing the OS.
what did you find out for ports?