Learn how to secure your system and implement QoS using real-world scenarios for networks of all sizes Implementing Packet filtering, NAT, bandwidth shaping, packet priority using the netfilter / iptables, iproute2, Class-based queuing (CBQ) and Hierarchical Token Bucket (HTB) Designing and implementing various types of five real-world firewalls and QoS scenarios ranging from small SOHO offices to large scale ISP network that includes many of the city Building intelligent networks by marking, queuing, and prioritizing traffic In Detail Firewalls are used to protect your network from the outside world. This book shows you how to implement Linux firewalls and Quality Service by using practical examples from very small to very large networks. The next section of this book covers 5 real-world network that we design the security policies, build the firewall, setup the script, and check our installation. Who is this book written for? This book is intended for Linux Network administrators with some understanding of Linux security threats and issues, or one who is interested in securing their systems behind a firewall.