Designing and Implementing Linux Firewalls and QoS using netfilter, iproute2, NAT, and L7-filter

Abstract

Chapter 1 is a brief introduction to networking concepts. It covers the OSI and TCP/IP networking models with explanations of their layers, TCP and UDP as Layer 4 protocols, and then rounds off the chapter with a discussion on IP addresses, Subnetting, and Supernetting. Chapter 2 discusses possible security threats and vulnerabilities found at each of the OSI layers. The goal here is to understand where and how these threats can affect us and to stay protected from attackers. It then rounds off the discussion by sketching out the basic steps required to protect the services that run on our system.