Why Network Security Matters
Network security is one of the most important aspects of enterprise networking. As data travels across switches and routers, it must be protected from unauthorized access, manipulation, and misuse. This topic introduces the core mechanisms that help you secure traffic, control access, and verify user identities across network devices.
Access Control
You’ll begin with Access Control Lists (ACLs), a fundamental security tool that filters traffic based on IP addresses, protocols, and ports. Then, you’ll explore authentication and AAA concepts, learning how Authentication, Authorization, and Accounting work together to enforce user access policies using methods like TACACS+ and RADIUS. You’ll also configure secure remote access using SSH to protect device management sessions.
Securing the Network Edge
Finally, you’ll study port-based security mechanisms that protect the network edge, including Port Security, DHCP Snooping, and Dynamic ARP Inspection (DAI). These features prevent common Layer 2 attacks and ensure device trustworthiness. By mastering these techniques, you’ll gain the skills to design and maintain secure networks that protect both infrastructure and users, forming a strong foundation for advanced security practices.