Network devices and physical components: routers, switches, and APs; ports and interfaces (RJ-45, fiber), SFP/GBIC modules, PoE. Cable types and categories (UTP/STP, multimode/single-mode), Ethernet standards and speeds. MTU, throughput, and reliability concepts. Best practices for installation, labeling, and Layer 1 troubleshooting.

Core OS concepts for desktop and server: processes, services, memory, and file systems. CLI tools (PowerShell, Bash) and basic networking tasks: IP/DNS/DHCP, local firewall, drivers and updates. Diagnostics with ping, tracert, ipconfig/ifconfig, netstat. Virtualization basics and snapshots for lab environments.

OSI/TCP-IP models, Ethernet and switching (VLANs, trunking, STP). IPv4/IPv6, subnetting and VLSM. Basic static and dynamic routing (single-area OSPF concepts), NAT/PAT and ACLs. Wireless fundamentals (SSID, channels, WPA2/3) and common IP services.

CIA triad, common threats, and attack surfaces. Device hardening and access control: AAA, local/remote methods, password and privilege management. Layer 2/3 controls: port security, DHCP snooping, DAI, ACLs. VPN basics, segmentation, and update policies.

Troubleshooting methodology (identify, hypothesize, test, verify, document). Tools: show/debug, syslog, SNMP, ping/traceroute, cable testers. Common Layer 1–3 issues (collisions, duplex, DHCP, DNS, routing) and evidence collection. Change management and user communication.