Book Image

OPNsense Beginner to Professional

By : Julio Cesar Bueno de Camargo
5 (1)
Book Image

OPNsense Beginner to Professional

5 (1)
By: Julio Cesar Bueno de Camargo

Overview of this book

OPNsense is one of the most powerful open source firewalls and routing platforms available. With OPNsense, you can now protect networks using features that were only previously available to closed source commercial firewalls. This book is a practical guide to building a comprehensive network defense strategy using OPNsense. You’ll start with the basics, understanding how to install, configure, and protect network resources using native features and additional OPNsense plugins. Next, you’ll explore real-world examples to gain in-depth knowledge of firewalls and network defense. You’ll then focus on boosting your network defense, preventing cyber threats, and improving your knowledge of firewalling using this open source security platform. By the end of this OPNsense book, you’ll be able to install, configure, and manage the OPNsense firewall by making the most of its features.
Table of Contents (25 chapters)
1
Section 1: Initial Configuration
6
Section 2: Securing the Network
13
Section 3: Going beyond the Firewall

Firewall aliases

To introduce you to aliases, let's start with a little story.

Let's imagine that you oversee an OPNsense firewall in a network with thousands of hosts, dozens of network segments, and a lot of VPN tunnels. This scenario will probably (considering good security practices) demand a lot of different rules to control host traffic, right? So, this will easily produce more than a thousand rules (yes – this part is based on a real example!), and managing each host individually using the one rule per host approach can increase this number to tens of thousands of rules incredibly quickly, becoming a nightmare to anyone in charge of managing the firewall!

Now, imagine it being possible to group hosts by access profile, selecting both source and destination hosts and adding them to lists, and then creating firewall rules based only on these lists.

This will drastically reduce the number of rules, turning the nightmare into the firewall ruleset of dreams...