Security+ ยท 3.0 Security Architecture
OSI model
A 7-layer conceptual model for network communication: Physical, Data Link, Network, Transport, Session, Presentation, Application. Cable Ethernet IP TCP . HTTP.
How this shows up at NCAE
When debugging: 'Is the problem L1 (cable)? L2 (switch)? L3 (routing)? L4 (port filter)? L7 (app config)?' Most NCAE issues are L3 (routing/NAT), L4 (firewall), or L7 (service config).
Error patterns associated with this term
Competition failures where this Security+ concept applies.