First, users must use apt-get update to update our software information. After completion, install the required service software, such as UFW.2 certificate replacement Let’s install our simple firewall UFW. After installation, use sudo ufw status verbose to check the current settings of the firewall. Linux security settings and Apache2 certificate replacement Let UFW start the service by default when booting.
Linux security settings and Apache2 certificate replacement By default, the author has turned off the firewall completely, leaving only the canada dataset rules for SSHing his own device to this host. These two rules: Linux security settings and Apache2 certificate replacement Linux security settings and Apache2 certificate replacement You can choose to default to fully on or default to fully off.
The author recommends defaulting to fully off, and then add the rules to be enabled. After installing openssh-server, I also added the devices that I will use the remote desktop to the whitelist. I want to install SSH here because it is convenient for the author to use my own computer for remote (putty) connection operations. Linux security settings and Apache2 certificate replacement To delete a firewall rule, you can use sudo ufw status numbered to see what rule number it is.