11 Networking Fundamentals
This chapter covers
- Network types and devices
- Addressing (including physical and logical ports)
- Networking models
- Network segmentation and Virtual Private Networks (VPNs)
Computer networks can range from small, local systems that connect a few devices to massive, global infrastructures, such as the Internet, which connects billions of systems worldwide. Regardless of their size, networks enable devices to exchange information and share resources, making them essential for communication, collaboration, and business operations.
This connectivity also introduces security risks, however. For example, attackers may attempt to gain unauthorized access to systems, intercept communications, manipulate network traffic, or disrupt critical services. Compromising a single device can sometimes provide a path to many others. Consequently, cybersecurity professionals must understand how networks operate to identify risks and implement effective security controls.
This chapter provides an overview of the fundamental concepts of computer networking. We will examine the components that enable communication, including endpoints, network devices, and communication links. We will explore common networking devices, such as hubs, switches, routers, firewalls, proxies, and wireless access points, and discuss how they collaborate to transfer data across networks.