Subnetting Made Simple: Carving Up IP Networks
Subnetting looks intimidating but it's just organized division. Learn how subnet masks, CIDR, and hosts-per-subnet work — with a clear worked example.
Cisco Router Hardening: A Baseline for Maximum Performance & Security
A hands-on baseline for taking a Cisco IOS router from box-fresh to production-ready — secure access, sane interfaces, routing, and the hardening steps most people skip.
Inside a Firewall: How It Decides What Gets In and What Gets Dropped
From simple packet filtering to stateful inspection and next-gen deep packet analysis — how firewalls decide what gets in, what gets dropped, and why.
Multi-Area OSPF in GNS3: A Cisco + Juniper Multivendor Lab
Build a multi-area OSPF network in GNS3 across three network operating systems — Cisco IOS, IOS-XE and Juniper Junos. Area 0 backbone, an ABR, the multivendor gotchas that break adjacency, and the show commands that prove it works.
Cisco IOS Lab: EIGRP Route Summarization for Scalable Networks
Big routing tables are slow to converge and easy to break. In this Cisco IOS lab I use EIGRP manual summarization to collapse a sprawl of subnets into a single advertised route — shrinking the table, speeding convergence, and containing query scope, with the exact config and the show output that proves it.
Cisco ASAv Multi-DMZ Configuration and RIP Routing Architecture
A hands-on Cisco ASAv lab: stand up two isolated DMZ segments, publish a web server safely, contain the blast radius with security levels and ACLs, and run a RIPv2 routing architecture across the inside LAN — full config plus the tests that prove it works.
Allowing ICMP Traffic Through the Cisco ASA Firewall
Why ping dies at the Cisco ASA — and how to fix it. Enabling ICMP inspection across a dual-EIGRP GNS3 lab, with the config and the verification tests.
Hardening Your Home Network with a Next-Gen Firewall
A practical walkthrough for turning a basic home router setup into a segmented, defensible network using pfSense or OPNsense.
OSPF vs EIGRP: Choosing the Right Interior Routing Protocol
Both OSPF and EIGRP can route your internal network well — but they get there very differently. Here is a practical guide to picking the right one for your topology.