Simple packet filters will soon be a thing of history. Even the open-source community is moving toward Next-Generation Firewalls. OPNsense, a leader in intrusion detection, web filtering and anti-virus, is also a leading player. No network is too small to be targeted by an attacker. Even home networks, washing machine, and smartwatches, are at risk and require a safe environment. Firewalls are an important part of the security concept. They protect computers and networks from known and unknown threats. A firewall will offer the best protection if it is easy to use, has well-known functions, and is placed in the right place. OPNsense takes on the challenge of meeting these criteria and does so in different ways. This book is an ideal companion to help you understand, install and set up an OPNsense Firewall.