3.2 Network Hardware and Software

Hardware that controls traffic

Routers direct data between networks using IP addresses, while switches connect devices within a local network using MAC addresses. Firewalls (hardware or software) filter incoming/outgoing traffic based on security rules, blocking unauthorized access while allowing legitimate communication.

Detecting and preventing intrusions

An IDS (Intrusion Detection System) monitors network traffic and alerts administrators to suspicious activity but doesn't block it. An IPS (Intrusion Prevention System) goes further — it actively blocks or stops detected threats in real time, making it more proactive than an IDS.

Access points and network segmentation

Wireless access points (APs) let devices connect to a wired network via Wi-Fi and can be secured with encryption protocols like WPA3. VLANs (Virtual Local Area Networks) logically segment a physical network into smaller groups, improving security and reducing broadcast traffic by isolating sensitive systems.

Key terms

Router

A device that directs data between different networks using IP addresses.

Switch

A device that connects devices within a local network using MAC addresses.

IDS vs IPS

IDS detects and alerts to suspicious activity; IPS actively detects and blocks threats.

Firewall

Hardware or software that filters network traffic based on security rules.

VLAN

Virtual Local Area Network — logically segments a physical network to isolate systems and reduce traffic.

Try an AP-style question

Which device forwards frames using MAC addresses within a LAN?

1. Modem
2. Switch
3. Router
4. Firewall