Networking guides & tutorials
Technical guides for understanding networks, troubleshooting real failures, working with Linux and routing software, and preparing for certification exams with a clear plan.
OSPF Neighbors Not Forming? A Step-by-Step Troubleshooting Guide
A state-by-state OSPF adjacency troubleshooting guide covering timers, areas, authentication, network type, MTU, router IDs, and missing routes.
Published August 24, 2026
VLAN vs Subnet: How VLANs, Subnets, and Trunks Actually Work Together
Understand the Layer 2 and Layer 3 boundaries between VLANs and subnets, then trace access ports, 802.1Q trunks, gateways, and inter-VLAN routing.
Published August 24, 2026
How Routers Choose a Route: Longest Prefix Match, Administrative Distance, and Metrics
Learn the order of route selection: longest-prefix match, source preference, protocol metrics, next-hop resolution, and installation into the FIB.
Published August 24, 2026
IP Address Works but Hostname Doesn’t? A DNS Troubleshooting Guide
Trace a hostname failure from resolver configuration and reachability through dig, search domains, caches, DNS response codes, and applications.
Published August 24, 2026
MTU vs MSS Explained: Why VPNs and Tunnels Break Large Packets
Diagnose small-packet success and large-packet failure with MTU, TCP MSS, encapsulation overhead, fragmentation, and Path MTU Discovery.
Published August 24, 2026
FRRouting and the Linux Routing Table: How Routes Reach the Kernel
How FRRouting protocol daemons, Zebra, and the Linux kernel cooperate, and how to troubleshoot a route that exists in FRR but not in forwarding.
Published August 18, 2026
5 Common Subnetting Mistakes That Break Real Networks
Five subnetting errors that cause asymmetric reachability, overlapping routes, bad gateways, and partial connectivity, with practical diagnostics.
Published August 18, 2026
Linux Network Namespaces Explained: Build a Virtual Network on One Host
Use namespaces, veth pairs, bridges, and Linux routing to model hosts and routers on a single machine.
Published August 18, 2026
How to Study for the CCNA Exam (200-301)
How the 200-301 blueprint is weighted, what order to study topics in, and the mistakes that slow down most first-time takers.
How to Study for CompTIA Network+ (N10-009)
Why Network+'s vendor-neutral, troubleshooting-heavy format catches people who studied Cisco-first, and how to prepare for it directly.
How to Study for CompTIA Security+ (SY0-701)
How SY0-701 is weighted, why performance-based questions reward applied practice, and what a networking learning platform can and can't cover for this exam.
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