Tutorials & mental models.
Short, opinionated walk-throughs of the CCNA® topics that actually trip people up. New post every couple of weeks.
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- ccnaccna-v2examstudy-plan
CCNA v1.1 Ends February 2, 2027: Take It Now or Wait for v2.0? A Date by Date Plan
The last day to sit CCNA 200-301 v1.1 is February 2, 2027. Work backwards from that date: when to book, where retakes and Exam Safeguard Plus fit, what the US holidays do to your schedule, and a simple rule for choosing v1.1 or v2.0.
Read post → - ccnaccna-v2automationaiansibleexam
CCNA v2.0 AI Domain, Objective by Objective: Agentic AI, Prompts, Ansible, SNMP and Syslog
Domain 5.0 of the 2027 CCNA covers agentic AI, choosing a prompt, network management approaches, SNMP, Ansible and syslog. What each objective really asks, with practice prompt questions and a working Ansible playbook.
Read post → - ccnaautomationccna-automationexamcareer
CCNA Automation vs the Automation Domain on the CCNA: Which One Are You Studying?
Since February 2026 there is a certification called CCNA Automation, and the regular CCNA also has an automation domain. They are different exams with different skills. Here is how to tell them apart and which one to study.
Read post → - ccnalabspacket-tracerciscocareer
CCNA Labs on Chromebook, Mac, or iPad: No Downloads, Browser Only (2026)
Practice real Cisco IOS, WLC and Palo Alto CLI labs on a Chromebook, Mac or iPad, right in the browser: no VM, no download and no Packet Tracer install.
Read post → - careerccnainterviewresumenoc
NOC Engineer Resume + Interview: How to Land Your First US Networking Job in 2026
The exact resume format, 12 must-list skills, and the whiteboard questions US hiring managers actually ask a NOC / Tier-1 network engineer candidate. Written for CCNA-fresh, career-transitioning applicants.
Read post → - ccnaciscotroubleshootingioscareer
Cisco Router Password Recovery: 2026 Step-by-Step (ISR + Catalyst + IOS-XE)
Recover a lost enable password on a Cisco router or switch: the ROMMON steps for ISR routers, how Catalyst switches differ, and the steps most guides skip.
Read post → - ccnacdplldplayer2
CDP vs LLDP: Cisco's Neighbor Discovery vs the Vendor-Neutral Way
The two Layer-2 discovery protocols on every Cisco lab: CDP (Cisco proprietary, on by default) and LLDP (IEEE 802.1AB, off by default). When to use which, security implications, and the show commands the CCNA tests.
Read post → - ccnafhrphsrpvrrpglbp
HSRP vs VRRP vs GLBP: Which First-Hop Redundancy for CCNA (and Real Networks)
HSRP vs VRRP vs GLBP compared: Cisco vs IETF standard, active/standby vs load balancing, which one to configure, and the CCNA exam details to know.
Read post → - ccnaaclaclsospffundamentals
Cisco Wildcard Masks: ACLs & OSPF Without Confusion
The mental model for Cisco wildcard masks. When to use them (ACLs, OSPF), how to convert from a subnet mask, and the #1 mistake that breaks half the labs.
Read post → - ccnatrunksvlansinter-vlan-routing
Cisco Trunking Best Practices (Without Causing Outages)
Learn the SOPs for configuring Cisco trunk links in enterprise networks. Avoid the common switchport trunk allowed vlan typo and master DTP and Native VLANs.
Read post → - aisecuritynetopscompliancechatgptgenai
Don't paste that config into ChatGPT: safe GenAI for netops
A senior network engineer's field guide to using LLMs for NetOps without leaking configs, keys or topology. What actually leaks in a show run, the compliance exposure, a working sanitizer script, prompt patterns that work, and enterprise + self-hosted options compared.
Read post → - ccnastpspanning-treelayer-2-securityswitchingtroubleshooting
BPDU Guard vs Root Guard vs Loop Guard: When to Use Which (CCNA)
CCNA tutorial on Cisco STP protection: BPDU Guard, Root Guard, and Loop Guard. What each blocks, where to apply them, and the real outage each one prevents.
Read post → - ccnafundamentalsnetwork-plustroubleshooting
TCP 3-Way Handshake Explained: SYN, SYN-ACK, ACK (CCNA)
The TCP 3-way handshake for CCNA: what SYN/SYN-ACK/ACK actually carry, why it's three packets not two or four, and the states Wireshark shows you.
Read post → - ccnaawscloud-networkingus-careerscertifications
CCNA vs AWS Advanced Networking: which one, when, and why
Cisco's CCNA and AWS's Advanced Networking Specialty overlap in name only. Which one fits your US networking career trajectory, whether you should do both, and what the national pay data says.
Read post → - ccnanetwork-plusus-careerscertifications
CCNA vs Network+: which for a US networking career in 2026
Cisco's CCNA and CompTIA's Network+ overlap on paper but target different careers. Which one US employers actually want, which pays more, and which order to sit them if you're going to do both.
Read post → - ccnaospfroutingtroubleshooting
OSPF timers, DR/BDR election, and why yours is stuck in EXSTART
The three OSPF problems that trip up every CCNA candidate: timer mismatches that never form a neighbor, DR/BDR election producing an unexpected router as DR, and the classic EXSTART/EXCHANGE stall from an MTU mismatch. With show commands, real numbers, and the fixes.
Read post → - ccnaospfeigrprouting
OSPF vs EIGRP: which one for CCNA and real US networking work
A candid comparison of OSPF and EIGRP: what the CCNA 200-301 exam tests on each, where each one is actually deployed in US enterprise networks, and how to answer the interview question about picking between them.
Read post → - ccnastatic-routingrouting
Static routing: floating routes, admin distance, and defaults
Everything you need to configure static routes with confidence: next-hop vs exit-interface, admin distance, floating statics as backup, the default route ('quad zero'), and why the wrong syntax silently drops your recursive lookup.
Read post → - ccnaipv6slaacrouting
IPv6 for CCNA: SLAAC, EUI-64, and the boot sequence
The IPv6 the CCNA actually tests: address structure, EUI-64, SLAAC vs DHCPv6, link-local vs global, and the CLI to bring hosts up without a DHCP server.
Read post → - ccnaetherchannellacpswitching
EtherChannel with LACP: bundling four links into one Port-channel
How to bundle multiple switch uplinks into a single logical Port-channel so STP stops blocking your redundant cables. LACP vs PAgP vs static, mode combinations that actually form a bundle, load-balance methods, and the diagnostic commands.
Read post → - ccnaport-securitydhcp-snoopingdailayer-2-security
Layer 2 hardening: Port Security, DHCP Snooping, and DAI in one lab
The three access-layer defenses against the most common L2 attacks: MAC flooding, rogue DHCP servers, and ARP spoofing. How they interact, the trust-port model, sticky-MAC pros and cons, and the diagnostic commands when something goes err-disabled.
Read post → - ccnaaclsecurity
Standard vs Extended ACL: which one to use when
A practical breakdown of Cisco IOS ACL types. When a one-line standard ACL is the right tool, when you need extended for protocol + port filtering, where to place them, and the mistakes that make ACLs silently do nothing.
Read post → - ccnahsrpfhrproutingredundancy
HSRP walkthrough: how default gateway redundancy actually works
HSRP explained: one virtual IP shared by two routers, active and standby election, priority, preempt and tracking, the show commands, and the virtual MAC.
Read post → - ccnaspanning-treestpswitching
Spanning Tree root bridge election: the mental model
How switches decide which one becomes the STP root bridge, what happens when priorities tie, why lowering priority is safer than lowering MAC, and how to force the root to sit where you actually want it.
Read post → - ccnaip-connectivityinter-vlan-routingsvi
Inter-VLAN Routing: SVIs vs Router-on-a-Stick (CCNA)
Free CCNA-level inter-VLAN routing tutorial for US networking learners. Why VLANs can't talk by default, router-on-a-stick with dot1Q sub-interfaces, the Layer-3 switch SVI method real networks use, and the #1 mistake that leaves SVIs up but routing dead.
Read post → - ccnaip-servicesdhcpdora
DHCP: DORA, Scopes, and the ip helper-address Relay (CCNA)
Free CCNA-level DHCP tutorial for US networking learners. The DORA exchange step by step, why every message is a broadcast, the Cisco IOS server config, ip helper-address relay across subnets, and the show commands that prove leases are landing.
Read post → - ccnaccnpsecuritydhcp-snoopingdynamic-arp-inspectionip-source-guard
Layer 2 Security: DHCP Snooping, DAI, and IP Source Guard (CCNA)
How DHCP snooping, Dynamic ARP Inspection, IP Source Guard, port security and 802.1X work together to secure a Cisco access port, with config and show commands.
Read post → - ccnaip-servicesnatpat
NAT & PAT: Inside Local, Inside Global, and Overload (CCNA)
Free CCNA-level NAT and PAT tutorial for US networking learners. Static vs dynamic vs PAT/overload, the four inside/outside local/global terms decoded, the config, and the show commands that prove it works.
Read post → - ccnaexamccna-v2
CCNA v2.0 (2027): What's Changing in the 200-301 Exam
What changed in the CCNA 200-301 v2.0 blueprint: a new AI domain, more hands-on troubleshooting, five domains instead of six, and the Feb 3, 2027 start date.
Read post → - ccnasecurityacl
Cisco ACLs: Implicit Deny, Wildcards, and the 10-Second Read
Free CCNA-level tutorial on Cisco ACLs for US networking learners. Implicit deny, wildcard masks, in vs out direction, and how to read any ACL in 10 seconds.
Read post → - ccnaswitchingvlans
VLANs Explained: Trunks, Access Ports, Native VLANs (CCNA Tutorial)
A free CCNA VLAN tutorial: trunks, access ports, 802.1Q tagging and native VLAN gotchas, with the mental model that makes it all click in 15 minutes.
Read post → - ccnaroutingospf
OSPF in 12 Minutes: The Mental Model Before the Commands (CCNA)
How OSPF works, told as a story: the LSDB, SPF, neighbors and the DR/BDR election, before you type your first router ospf 1 command on a Cisco router.
Read post → - ccnaswitchingtroubleshootingvlanstrunks
'My Trunk Won't Pass VLAN 20': A 6-Step Debug Workflow (CCNA)
Step-by-step troubleshooting for the classic CCNA-lab moment when you've configured the trunk but VLAN 20 traffic isn't reaching the other switch.
Read post → - ccnacareercertifications
The Free Certificates to Earn Before Your CCNA
Free Cisco and cloud certificates that strengthen a junior network engineer resume before the paid CCNA exam, in order for help desk and college learners.
Read post → - ccnasubnettingfundamentals
Subnetting in Your Head: The Magic-Number Trick (CCNA)
The one method that turns CCNA subnetting from 'do the binary math' into 'glance at the mask, subtract, done'. Worked examples for /27, /28, /22, /21.
Read post →