Port Numbers Worth Memorizing for Network+ (and Which Ones You Can Skip)
Network+ port-number memorization is a slog. Here's the ranked list — must-memorize, nice-to-know, and safely-skip — based on what the N10-009 actually tests.
Posts tagged: Networking
OSI vs TCP/IP Layer Mapping — A Cheat Sheet for the N10-009 Exam
OSI 7-layer model mapped to the TCP/IP 4-layer model with every protocol, PDU name, and exam-trap clarified. The cheat sheet that turns layer questions into …
Subnetting Without a Calculator — The Magic-Number Method
Subnet any IPv4 mask in under 30 seconds without a calculator. The magic-number method explained, the /29 walkthrough, and the 256-rule trick that works on any …
ARP Poisoning: Intercepting Traffic on Your Own Network
Technical deep dive into ARP spoofing: how gratuitous ARP poisons caches, Scapy MitM scripts, Ettercap credential capture, DAI on Cisco Catalyst, and arpwatch …
Designing a Secure Campus Network: The SE's Reference Architecture
A complete reference architecture for secure campus networks — 3-tier design, ISE placement, firewall positioning, wireless security, and a 500-user bill of …
SSL Stripping: Downgrading HTTPS to HTTP Without the User Noticing
How SSL stripping intercepts HTTPS traffic via HTTP rewrites, where HSTS and HSTS preloading defend against it, and what sslstrip still bypasses in 2026.
VLAN Hopping: Jumping Between Network Segments You Shouldn't Access
Technical breakdown of VLAN hopping via switch spoofing and double tagging, with Scapy exploit code, Cisco IOS hardening configs, and PCI DSS segmentation …
Man-in-the-Middle on Wi-Fi: What Evil Twin Access Points Actually Look Like
Technical deep dive into Evil Twin AP attacks: hostapd setup, PMKID capture, WPA2 cracking with hashcat, deauth floods, and enterprise WIDS defenses.
Cisco SD-WAN vs Traditional VPN: What to Tell the Customer
Architecture, performance, security, and cost comparison of Cisco SD-WAN vs traditional IPsec VPN — with migration paths, ROI talking points, and customer …
BGP Hijacking: How Attackers Reroute the Internet Itself
Deep dive into BGP hijacking mechanics, real incidents including the 2018 AWS Route 53 attack, RPKI/ROA validation, BGPStream monitoring, and prefix filtering …