So if my first rule allows all traffic and my last rule allows none, then all traffic is allowed. Once a rule is matched, no more rule checking occurs. See Iptables How To, Debian, and archlinux.įirewall rules are processed from top to bottom. Iptables is quite powerful but also sometimes complex, so do try to learn more before blindly applying these rules. Rules for iptables can sometimes be a bit touchy so make certain that you are able to connect to your pi via console until certain of your settings. Iptables is currently running on your pi but it is set to allow all traffic. It can be made more secure with iptables which will only allow the types of traffic you permit. Without a firewall, your pi is functional and connected. It is an important and effective part of your pi's security and in some use cases is required.

Iptables is used to control packet filtering, Network Address Translation (masquerading, portforwarding, transparent proxying), and special effects such as packet mangling.

Restart iptables