* * deny — ~/lab

lab

Small, contained sandboxes for the concepts security engineers deal with daily -- the kind you use constantly but rarely see animated. Pick a mode, run it, watch what actually changes. Everything here is entirely client-side and simulated unless a lab says otherwise on its own page -- one of the labs below has a small, clearly-labeled live component, and it says so up front.

live

Policy Console Sandbox

Eight generic policy modules — forwarding, URL filtering, DNS, cloud app control, and more — one core skill practiced in each: trace which rule fires in a table, read top-down, first match wins.

live

Forward Proxy vs. Reverse Proxy

Watch the same request animate hop by hop through a forward proxy and then a reverse proxy, and see exactly what each hop knows: destination visibility, where TLS terminates, what headers get added. The vocabulary you use daily, finally drawn out.

live

What a DNS Query Leaks

Build a real DNS query byte by byte, send it over plaintext, DNS-over-TLS, or DNS-over-HTTPS, and see which observers stop being able to read the hostname -- and which one never does, no matter which transport you pick.

live

What TLS Inspection Actually Sees

Toggle inspection on and off against a simulated HTTPS connection. SNI, certificate, and body -- see exactly which one changes when a proxy terminates and re-signs the connection, and which one was never hidden in the first place.

live

How Cloudflare Sees Your Request

Part one is real: see the actual headers Cloudflare's edge just added to the request that loaded this page. Part two is a labeled simulation of how you'd stop someone from bypassing that edge and hitting your origin directly.