OSI and TCP/IP Models
IP Addressing and Subnetting
Routing and Switching Basics
Anycast vs Unicast vs Multicast
TCP vs UDP
TCP Handshake and Connection Termination
Ports and Protocols (HTTP, HTTPS, DNS, SSH, etc.)
DNS Resolution Process
DHCP and ARP
Firewall and NAT
HTTP Lifecycle and Status Codes
TLS/SSL Handshake
CDN and Caching
Packet Flow (from browser to server and back)
Latency, Bandwidth, Throughput
VPN and Tunneling (SSH tunnel, IPSec, etc.)
Network Security (DDoS, MITM, Firewalls, IDS/IPS)