Lesson 2. Cybersecurity Fundamentals: Protecting Networks from Malicious Attacks

Firewall

Hardware or software that filters incoming and outgoing network traffic based on set rules, acting as the first line of defense against unauthorized intruders.

Packet Filter Firewall

A type of firewall that inspects data packets and decides whether to allow them to enter or leave a network based on predefined rules.

Application Filtering Firewall

A type of firewall that controls input, output, and access by applications or services, blocking applications, content, or specific words/phrases.

Stateful Firewall

A type of firewall that allows incoming requests only if they match an outgoing request, tracking established connections to filter traffic.

DMZ (Demilitarized Zone)

A network segment that separates public-facing services (e.g., web servers) from internal services (e.g., network), providing an additional layer of security.

Router

A network device that routes traffic within a network and forwards packets based on IP addresses.

Switch

A network device that facilitates packet delivery based on MAC addresses, learning and storing MAC addresses to improve network efficiency.

Load Balancer

A device that distributes network traffic across multiple servers to prevent overload and ensure efficient processing.

Proxy

A device or server that forwards packets between clients and servers, hiding internal IP addresses and providing security benefits.

NAT (Network Address Translation)

A method that remaps private IP addresses to public IP addresses, allowing multiple devices to share one public address and enhancing security.

Reverse Proxy

A proxy that protects a web server by inspecting incoming requests and blocking malicious traffic.

VPN Concentrator

A device that decrypts incoming packets from a Virtual Private Network (VPN) and encrypts outgoing packets, ensuring secure communication between remote users and the network.