Communication and Network Security
3 lessons ~2h
Networking through a security lens. The OSI and TCP/IP models anchor everything; layer on secure protocols, modern segmentation (VLANs, micro-segmentation, zero trust), wireless and cellular, SDN/SD-WAN, and secure channels for voice, remote access, and third-party connectivity.
Exam tips — what to expect
- 1Know the OSI 7 layers cold and which device, protocol, and attack lives at each layer — many questions are really "what layer?" in disguise.
- 2Memorize common ports and the secure-vs-insecure protocol pairs: Telnet→SSH (22), HTTP→HTTPS (443), FTP, and SSL (deprecated) → TLS.
- 3Expect "MOST secure" comparisons — firewall types (packet filter → stateful → proxy), EAP methods (EAP-TLS strongest), and wireless (WEP < WPA < WPA2 < WPA3). Pick the strongest current option.
Recommended reading
Lessons
- 4.1
Apply secure design principles in network architectures
Know the OSI 7 layers and TCP/IP mapping cold, where each secure protocol operates (IPSec, SSH, TLS), and modern segmentation strategies up to micro-segmentation and zero trust.
~55 min
- 4.2
Secure network components
Secure the physical and access layers of the network — infrastructure operation/redundancy, transmission media, NAC, and endpoint security.
~30 min
- 4.3
Implement secure communication channels according to design
Apply secure-channel design to real services: voice/video/collaboration, remote access, data communications, and third-party connectivity.
~30 min
Domain 4 Exam · 50 questions
Complete all 3 lessons above, then take the 50-question exam. Pass at 70% to unlock the next domain.