Who is teaching this
I'm Taylor Thomas.
It's my privilege to share what I've learned — and to help build the next generation of engineers.
I design and deploy Cisco security for a living, as a field engineer for large public-sector and critical-infrastructure organisations — the environments where a firewall policy is reviewed by an accreditor, an identity change touches thousands of endpoints, and a mistake is not a lab reset but a phone call. That is the work these lessons come out of, and it is what I want to hand on.
Before that I served in the military, where I learned that a procedure is only as good as the person who can follow it at three in the morning. It is why the lessons here are built the way they are: one pass — read it, understand it, see it, apply it, validate it — with nothing left for you to assemble yourself.
What I work on
If it is on a Cisco security exam blueprint, there is a good chance I have deployed it, broken it, and fixed it for someone who could not afford the downtime.
Identity Services Engine and 802.1X at scale
Secure Firewall, FTD and zero-trust access
Secure Access and SD-WAN
Email Threat Defense
Secure Endpoint and XDR
Cyber Vision and OT/ICS security
Compliance automation against DISA STIGs
Why this site exists
Most Cisco security training is written by people who have read the configuration guide. I wanted the other kind — written against equipment that is actually running, by someone who has had to make these products work where hand-waving does not survive contact. The difference shows up in exactly the parts a guide cannot give you: which option to choose, what breaks at scale, and what the failure looks like on the console. I was helped along the way by engineers who shared what they knew; this is my turn.
How the lessons are made
An automated pipeline drafts, criticises and revises each lesson against a written standard — accuracy checked against Cisco's own documentation, configuration run on real devices, figures drawn from one lab topology so nothing contradicts anything else. Then I review it. The pipeline does the volume; the judgement is mine, and the "report an error" link on every page reaches me.
Corrections are made against the Cisco documentation, dated, and listed publicly on the updates page. How we build describes the pipeline and the gates in detail.
Credentials
CCIE #59770 — Enterprise Infrastructure and Security, one number, two tracks. Both are current and verifiable on Credly: Enterprise Infrastructure · Security
securitylessons.com is an independent publication. It is not affiliated with, sponsored by, or produced on behalf of Cisco Systems, Inc.; opinions and recommendations here are my own. Cisco, the Cisco logo, and product names are trademarks of Cisco Systems, Inc.