F2. Networking fundamentals

Outcome: you can explain how data moves across a network, build a small switched and routed network, and troubleshoot it from the cable up to the application.

Skills: OSI and TCP/IP models, cabling and connectors, Ethernet switching and VLANs, IPv4 and IPv6 addressing and subnetting, routing basics, Wi-Fi standards and security, common ports and protocols, DHCP and DNS basics, NAT and VPN concepts, SNMP and syslog, network troubleshooting tools.

Labs

1. Install Cisco Packet Tracer (free with a Cisco Networking Academy account). Build two VLANs on one switch, route between them with a router, and give both VLANs DHCP.
2. Subnetting drill: split a /24 for four departments of different sizes. Check your answers with a calculator only after you finish.
3. Install Wireshark. Capture and label a DHCP exchange, a DNS lookup, a TCP three-way handshake and the start of an HTTPS connection.
4. Read your home router's settings: DHCP range, DNS servers, Wi-Fi band and security mode, port forwarding. Screenshot first and change nothing you can't put back.
5. Run the command-line tools on Windows and Linux: ipconfig and ip, ping, tracert and traceroute, nslookup and dig, netstat and ss, arp.
6. Fault practice in Packet Tracer: a partner breaks one thing (wrong VLAN, wrong gateway, a shut interface, a duplicate IP). Find and fix it.

Prove it: the Packet Tracer file with a diagram and addressing table, an annotated Wireshark capture, and a write-up of the fault practice.

Certs: Network+ (all five domains: concepts 23%, implementation 20%, operations 19%, security 14%, troubleshooting 24%) and A+ Core 1 networking (23%). S1 builds on this in the full lab.

Gate: A+ Core 1 (220-1201) happens here, with one review week.