Inside the BHWSI server
What actually happens when someone opens bhwsi.com, and the locks along the way. No jargon left unexplained.
Conner McCarthy, October 2026
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server
A computer that never switches off
It's rented from Amazon and sits in one of their data centres. It's about as powerful as an everyday laptop, but it runs day and night.
Every BHWSI address leads to this one machine.
What happens when you open bhwsi.com
Every visit goes through the same front door, which reads the address and points you to the right room. The rest of this talk follows that path.
firewall
Three doors open. Every other one is locked.
A server has 65,535 numbered doors, called ports. The firewall ignores every knock except on three.
- Two doors for web visitors
- One door for the administrator
- Locked: each grey tile is 256 doors
HTTPS, TLS, certificate
Everything travels in a sealed envelope
Anyone who types the plain http:// address gets sent to https:// automatically. The ID card comes free from Let's Encrypt and renews itself before it expires.
nginx
One front door with a receptionist
Visitors never walk straight into a room. The receptionist opens the envelope, reads where you're going and walks you there.
The back rooms have no outside door at all.
attack filtering
Known break-in tricks are turned away at the door
Automated bots scan the whole internet for websites with known weak spots. When a new trick against the kind of software the website uses was discovered, the front door was taught to recognise it and refuse it.
SSH
The admin door takes a key, not a password
SSH is how the administrator reaches the server to fix and update things. A key file is like a house key that can't be guessed: without the file, there's no way in.
fail2ban
A bouncer for repeated wrong guesses
It keeps an eye on two sign-in points: the admin door and the AI helper. Too many failures in a short time and that address is shut out for a while.
database, API token
Records stay in the back room
The database has no outside door. Course files can't be downloaded directly; the learning site checks who you are first.
Moodle also has a pass for automated tools, called a token. It only works from inside the server, so a leaked one is useless.
MCP connector, OAuth
An AI helper that can look but not touch
Staff can ask Claude questions like "who's falling behind?" The helper reads learner progress and course health through a window, never a door.
You sign in first, and it uses a viewer-only account that can't change anything.
cron, patching, monitoring
One day on the server, minute by minute
- Every minute, the learning site does routine chores like sending forum emails.
- Every 15 minutes, a check raises the alarm if the disk is filling up.
Every day, security updates install themselves and a malware scan emails its results.
All the time, health reports go to a dashboard, with passwords and keys removed first.
Layers, not one lock
To reach course data, someone would have to get through every ring. If one fails, the next one is still standing.
Questions?