Firewall UFW
LxRoot automatically configures the Ubuntu ufw firewall which creates netfilter rules within the o/s kernel. The default configuration created by LxRoot includes all the rules you are likely to need to manage your hosting cluster.
If You are a SuperAdmin, You can navigate to Application > Linux Package Manager > UFW and manage your UFW Firewall. You can.
Unless you are an expert user, it is very important that this firewall is not disabled.
UFW manages the NAT rules responsible for outbound connectivity for your PHP and other application containers. Disabling it will result in containers losing internet access.
If you use an external firewall, this can be used in conjunction with ufw. You can use ufw to add any custom rules that you require. Please see the Ubuntu wiki or official documentation for more information on this.
LxRoot will soon include a UI for firewall rule management.