Understand a secure network
Build a mental model from packets to cloud access. Follow the sequence or open any note that catches your interest.
How data travels
- 01
OSI and TCP/IP models
Use OSI and TCP/IP layers to explain a browser request and separate physical, addressing, transport, and application problems.
- 02
IP addresses
Learn what IPv4 and IPv6 addresses identify, how private addressing works, and why an address in a log is not a person's identity.
- 03
Subnetting and CIDR
Understand CIDR prefixes and IPv4 subnet boundaries through a small /24-to-/26 example, including what subnetting cannot enforce.
Control the traffic
- 04
TCP and UDP
Compare streams and datagrams through application requirements, failure handling, and the evidence needed to understand a network exchange.
- 05
Domain Name System
Follow a DNS lookup through resolvers, authoritative servers, and caches, and learn why a resolved name is not proof that a service is trustworthy.
- 06
Firewalls
Understand traffic-policy enforcement, stateful inspection, rule ownership, and why permitting a connection does not authorize its application actions.
Design for trust
- 07
Network segmentation
Design meaningful security zones, define necessary communication, and verify that enforcement matches the boundaries drawn in the network diagram.
- 08
Zero trust
Understand resource-focused access decisions, identity and device evidence, and how zero trust works alongside existing controls.
- 09
Cloud shared responsibility
Assign ownership for each cloud control using the specific service boundary, then verify customer configuration instead of relying solely on provider assurance.
Keep connecting the dots.
Follow another path or take your next question into the library.
Find your next direction