Core

TCP/IP, the protocols and ports you must know, network attacks, and the defences: firewalls, IDS, VPNs.

1. 01Network models and the protocols that matterOSI vs TCP/IP, encapsulation, and the core protocols you must be able to reason about: IP, TCP, UDP, DNS, DHCP, ARP.~5 min read
2. 02Network attacksSniffing, spoofing, man-in-the-middle, DoS/DDoS and the local-network attacks that exploit trusting protocols.~4 min read
3. 03Firewalls, IDS/IPS, VPNs and segmentationThe defensive infrastructure of a network: how firewalls filter, how detection works, what a VPN actually protects, and why segmentation matters.~4 min read