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Every article on thelineman.ca — newest first. CCNA study breakdowns, Fortinet home lab notes, self-hosting war stories, and reference material. Looking for educational pieces only? See GUIDES. Looking for free Packet Tracer labs? See LABS.
★ STUDYING FOR THE CCNA? GO TO THE STUDY HUB ★ Every article on this list mapped to the official CCNA 200-301 exam blueprint ▶
PRACTICE
[ CCNA · SUBNETTING · PRACTICE ]
CCNA SUBNETTING PRACTICE QUESTIONS
(WITH ANSWERS EXPLAINED) Twelve worked subnetting problems — network & broadcast, host counts, masks, VLSM sizing, wildcards, and the magic-number method — each with a click-to-reveal answer. Try it, then check yourself. Q&A [ CCNA · OSPF · DR/BDR ] HOW IS THE OSPF DR/BDR ELECTED? Priority first, then Router ID — why the newest router almost never wins, how to force the DR with ip ospf priority, and why point-to-point links skip the election entirely. GUIDE [ CCNA · TRANSPORT · TCP/UDP ] TCP vs UDP:
THE TRANSPORT LAYER, MADE CONCRETE The 3-way handshake, ports and sockets, reliability vs speed, and the well-known port for every CCNA service — then watch it move in the live packet visualizer. BLOG [ CCNA · CAREER ] IS THE CCNA WORTH IT IN 2026?
AN HONEST TAKE A working network analyst's honest answer — the real case for it, the honest case against, who shouldn't bother, what it costs in time and money, and a clear way to decide. GUIDE [ CCNA · OSPF · LSA TYPES ] OSPF MULTI-AREA & LSA TYPES:
WHAT EACH LSA CARRIES Why OSPF carves the domain into areas, the four router roles (internal / backbone / ABR / ASBR), every CCNA-relevant LSA type (1, 2, 3, 4, 5, 7) with originator and flooding scope, and the five OSPF packet types tied to the adjacency state machine. GUIDE [ CCNA · IPV6 ] IPV6 FOR THE CCNA:
COMPRESSION, TYPES & EUI-64 The short IPv6 guide for the exam — 128-bit anatomy, the two compression rules, the six address types, and EUI-64 step-by-step. Paired with three free drill tools. GUIDE [ CCNA · ROUTING · OSPF ] OSPF EXPLAINED:
LINK-STATE ROUTING FOR THE CCNA No CLI — just the mental model. Distance-vector vs link-state, LSDB & SPF, areas, router-ID picking order, the process-ID trap, and wildcard masks. Read this before you touch the lab. GUIDE [ CCNA · OSPF · TROUBLESHOOTING ] OSPF ADJACENCY STATES:
WHY YOURS IS STUCK IN EXSTART Every OSPF state — DOWN, INIT, 2-WAY, EXSTART, EXCHANGE, FULL — and the one-line fix for each failure mode. MTU mismatch, one-way Hellos, flapping timers, and the troubleshooting decision tree. GUIDE [ NETWORKING · VPN · TROUBLESHOOTING ] THE 1500-BYTE LIE:
WHY YOUR VPN HANGS ON BIG FILES The VPN's up. Pings are 18ms. Web works. Then a 50MB download hangs at 4%. Here's the math, the captures, and the MSS-clamping fix — per platform. REFERENCE [ CCNA · REFERENCE ] SUBNETTING CHEAT SHEET:
CIDR, BLOCK SIZES & HOST COUNTS Every prefix /8 through /32 in one place. Subnet mask, block size, total addresses, usable hosts, and wildcard mask. Save the image or bookmark the page. GUIDE [ CCNA · SUBNETTING ] WHY SUBNETTING FINALLY
CLICKED FOR ME Three weeks of confusion. One diagram that changed everything. Here's the mental model that actually works — and why most guides start from the wrong end. TUTORIAL [ SELF-HOSTING · ANALYTICS ] DITCHING GOOGLE ANALYTICS
FOR UMAMI I self-host everything. My analytics should be no different. Here's the full Docker + Cloudflare Tunnel setup. BLOG [ HOME LAB ] FORTINET ON A BUDGET:
MY STACK EXPLAINED FortiGate 60F, FortiSwitch 124D, FortiAP 421E. Why Fortinet, what it cost, and what I've learned running enterprise gear at home. BLOG [ REAL TALK ] WHAT ENTERPRISE
NETWORKING LOOKS LIKE Two summers at Halton DSB taught me more than any textbook. Here's what nobody warns you about. BLOG [ MINDSET ] TRAINING FOR AN IRONMAN
TAUGHT ME HOW TO STUDY Olympic tri done. Half marathon done. CCNA done. The discipline is the same — only the protocol changes. TUTORIAL [ SELF-HOSTING · TROUBLESHOOTING ] WHY MY SITE WORKED
LOCALLY BUT NOT PUBLICLY Apache, DNS, Cloudflare Tunnel — every reason a self-hosted site fails publicly and how I fixed each one.
(WITH ANSWERS EXPLAINED) Twelve worked subnetting problems — network & broadcast, host counts, masks, VLSM sizing, wildcards, and the magic-number method — each with a click-to-reveal answer. Try it, then check yourself. Q&A [ CCNA · OSPF · DR/BDR ] HOW IS THE OSPF DR/BDR ELECTED? Priority first, then Router ID — why the newest router almost never wins, how to force the DR with ip ospf priority, and why point-to-point links skip the election entirely. GUIDE [ CCNA · TRANSPORT · TCP/UDP ] TCP vs UDP:
THE TRANSPORT LAYER, MADE CONCRETE The 3-way handshake, ports and sockets, reliability vs speed, and the well-known port for every CCNA service — then watch it move in the live packet visualizer. BLOG [ CCNA · CAREER ] IS THE CCNA WORTH IT IN 2026?
AN HONEST TAKE A working network analyst's honest answer — the real case for it, the honest case against, who shouldn't bother, what it costs in time and money, and a clear way to decide. GUIDE [ CCNA · OSPF · LSA TYPES ] OSPF MULTI-AREA & LSA TYPES:
WHAT EACH LSA CARRIES Why OSPF carves the domain into areas, the four router roles (internal / backbone / ABR / ASBR), every CCNA-relevant LSA type (1, 2, 3, 4, 5, 7) with originator and flooding scope, and the five OSPF packet types tied to the adjacency state machine. GUIDE [ CCNA · IPV6 ] IPV6 FOR THE CCNA:
COMPRESSION, TYPES & EUI-64 The short IPv6 guide for the exam — 128-bit anatomy, the two compression rules, the six address types, and EUI-64 step-by-step. Paired with three free drill tools. GUIDE [ CCNA · ROUTING · OSPF ] OSPF EXPLAINED:
LINK-STATE ROUTING FOR THE CCNA No CLI — just the mental model. Distance-vector vs link-state, LSDB & SPF, areas, router-ID picking order, the process-ID trap, and wildcard masks. Read this before you touch the lab. GUIDE [ CCNA · OSPF · TROUBLESHOOTING ] OSPF ADJACENCY STATES:
WHY YOURS IS STUCK IN EXSTART Every OSPF state — DOWN, INIT, 2-WAY, EXSTART, EXCHANGE, FULL — and the one-line fix for each failure mode. MTU mismatch, one-way Hellos, flapping timers, and the troubleshooting decision tree. GUIDE [ NETWORKING · VPN · TROUBLESHOOTING ] THE 1500-BYTE LIE:
WHY YOUR VPN HANGS ON BIG FILES The VPN's up. Pings are 18ms. Web works. Then a 50MB download hangs at 4%. Here's the math, the captures, and the MSS-clamping fix — per platform. REFERENCE [ CCNA · REFERENCE ] SUBNETTING CHEAT SHEET:
CIDR, BLOCK SIZES & HOST COUNTS Every prefix /8 through /32 in one place. Subnet mask, block size, total addresses, usable hosts, and wildcard mask. Save the image or bookmark the page. GUIDE [ CCNA · SUBNETTING ] WHY SUBNETTING FINALLY
CLICKED FOR ME Three weeks of confusion. One diagram that changed everything. Here's the mental model that actually works — and why most guides start from the wrong end. TUTORIAL [ SELF-HOSTING · ANALYTICS ] DITCHING GOOGLE ANALYTICS
FOR UMAMI I self-host everything. My analytics should be no different. Here's the full Docker + Cloudflare Tunnel setup. BLOG [ HOME LAB ] FORTINET ON A BUDGET:
MY STACK EXPLAINED FortiGate 60F, FortiSwitch 124D, FortiAP 421E. Why Fortinet, what it cost, and what I've learned running enterprise gear at home. BLOG [ REAL TALK ] WHAT ENTERPRISE
NETWORKING LOOKS LIKE Two summers at Halton DSB taught me more than any textbook. Here's what nobody warns you about. BLOG [ MINDSET ] TRAINING FOR AN IRONMAN
TAUGHT ME HOW TO STUDY Olympic tri done. Half marathon done. CCNA done. The discipline is the same — only the protocol changes. TUTORIAL [ SELF-HOSTING · TROUBLESHOOTING ] WHY MY SITE WORKED
LOCALLY BUT NOT PUBLICLY Apache, DNS, Cloudflare Tunnel — every reason a self-hosted site fails publicly and how I fixed each one.