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WBCHSE HS Cyber Security study materials
WBCHSE HS Cyber Security study resources

WBCHSE HS Cyber Security: Networking Fundamentals and Network Security

WBCHSE HS Cyber Security · Work through your exam, one topic at a time.

All guide sections

Networking Fundamentals and Network Security

Domain focus

Networking Fundamentals and Network Security tests how data moves and where controls sit: OSI and TCP/IP layers, IP addressing, ports, protocols, firewalls, IDS/IPS, VPNs, segmentation and DMZ design.

Core rules and concepts

  • TCP is connection-oriented; UDP is connectionless. Common ports identify services: 80 HTTP, 443 HTTPS, 22 SSH, 53 DNS, 3389 RDP.
  • A firewall filters traffic by rules; stateful firewalls track connections; ACLs apply permit and deny entries in order.
  • An IDS detects and alerts; an IPS can block inline. Neither replaces patching or authentication.
  • A VPN protects traffic in transit between endpoints; TLS protects application traffic; NAT translates addresses but is not a security control.
  • Segmentation limits lateral movement; a DMZ hosts public-facing services; least exposure means opening only required ports.

Worked example

A public web server must serve HTTPS to Internet users and be administered only from a management LAN. Rule logic: permit TCP 443 from any address to the web server; permit TCP 22 from the management subnet to the web server; deny all other inbound traffic; log denies. Reasoning: exposing 3389 or any-to-any traffic increases attack surface. The admin path is restricted by source address, not hidden by NAT.

Traps that cost marks

Do not say a firewall removes malware. Do not equate IDS with IPS. Do not think HTTPS hides the server IP or replaces authentication. Do not forget DNS uses UDP 53 for ordinary queries and TCP 53 for larger transfers or zone transfers. Do not call NAT a firewall. Do not permit all traffic because a service might need it.