Firewall FOR LINUX

Firewall is a handy set of scripts, including firewall, fwup, and fwdown. They work together to create an ipchains firewall. Plus, they offer different ways to manage network address and port translation. It’s super easy—just check out the policy file and tweak it to match your network setup and filtering rules.

Understanding the Policy File

The policy file has different sections where you’ll need to define a few things: first, which network interfaces are trusted or untrusted for this host; second, what role this host plays in your network setup; and third, what services can come in or go out along with the internal and external hosts that can connect to them. The design aims to make this process as straightforward as possible!

Detailed Guidance

Inside each section, you’ll find clear explanations and advice on topics like when to kick off the firewall. It also covers security risks tied to popular internet services and tips on how to allow them without compromising safety. This tool helps admins quickly get familiar with packet filtering so they can make smart security choices. You’ll be able to keep your network secure (at least regarding packet filtering) in no time! But hey, it won’t stop you from making bad decisions—you’ve been warned!

Key Features of Firewall

Here are some key features:

• Single Host (no forwarding or address/port translation)


• Forwarding (no address/port translation)


• Masquerading (outgoing M:1 NAPT)


• Port Forwarding (Masquerading + incoming 1:M NAPT)


• Alias Port Forwarding (Masquerading + incoming N:M NAPT)


• Static NAT (incoming and outgoing 1:1 NAT)

If you're interested in diving deeper into Firewall, check it out here!