Gary's Nightmare Shift.
Every door in the building is a port. Every visitor is a protocol. One morning everything goes wrong at once — and Gary learns what each door actually does.
Gary's coffee shop has numbered doors down the side of the building. Each door is for one type of visitor. The door number is the port. The visitor is the protocol.
Gary arrives at 6am. First disaster: someone broke in through Door 21 overnight and stole a filing cabinet full of recipes. The door was wide open — no lock, no cover. Anyone walking past could see exactly what was being carried out.
That's FTP — file transfer in the open, totally unencrypted. Port 21.
Worse, the burglar listened through Door 23 — a glass door Gary used to shout orders through to the kitchen. Passwords, stock codes, everything — the whole street heard it.
That's Telnet — cleartext remote access. Port 23. Gary's wife makes him nail both doors shut and replace them with Door 22 — a thick steel door with a deadbolt. Same jobs, but now nobody can see or hear a thing.
That's SSH — Port 22. Files securely? SFTP and SCP go through Door 22 as well.
8am. The postman shoves outgoing letters through Door 25 — anyone can push letters through without showing ID. Gary upgrades to Door 587 — same slot, but now you flash your badge first.
SMTP Port 25 = send without authentication. SMTP Submission Port 587 = authenticated sending.
Two postboxes for incoming. Door 110: the postman hands letters and immediately shreds his copy. Door 143: letters stay in the postbox too — readable from phone, laptop, anywhere.
POP3 Port 110 = download and delete. IMAP Port 143 = sync everywhere. Padlocked: IMAPS Port 993, POP3S Port 995.
9am. The serving hatch — Door 80. Customers hear everything: names, card details, orders. A customer complains. Gary installs frosted glass and a whisper slot — Door 443. Now orders are private.
HTTP Port 80 = the open web. HTTPS Port 443 = encrypted with TLS.
A woman asks for BestBeans.com. Gary points to the phone book on the wall — Door 53. Quick lookups through the small window (UDP). Copying the whole book? Full door (TCP zone transfer). That's DNS.
DNS Port 53 — UDP for queries, TCP for zone transfers.
A new shop across the street has no address yet. "I NEED A NUMBER!" The council desk shouts back the address over UDP. That's DHCP.
DHCP Ports 67/68 — hands out IP addresses over UDP.
TACACS+ encrypts the entire packet. RADIUS only whispers the password. Gary's wife asks which is more secure. Gary doesn't even hesitate. — Story 02 · Ports & Protocols
10am. Three stockroom doors left wide open overnight — Door 3306 (MySQL), Door 5432 (PostgreSQL), Door 1433 (Microsoft SQL). Anyone off the street could walk in. Gary nearly has a heart attack. His wife shouts: "THESE SHOULD NEVER FACE THE STREET."
Databases: MySQL Port 3306, PostgreSQL Port 5432, MSSQL Port 1433. Internal only. Never exposed.
11am. A staff directory — Door 389 — a big open binder anyone can flick through. His wife locks it in a glass case — Door 636. Same directory, now encrypted. She also installs a ticket booth — Door 88 — where staff prove who they are once and get a golden ticket that opens every door.
LDAP Port 389 = open directory. LDAPS Port 636 = encrypted. Kerberos Port 88 = golden ticket, prove once.
Lunchtime. Two bouncers. Door 1812, RADIUS: checks your name, cups his hand and whispers your password, but says everything else out loud. Fast, UDP. The WiFi bouncer. Door 49, TACACS+: takes you to a back room and whispers everything. Thorough, TCP. The Cisco bouncer.
RADIUS Port 1812/UDP — encrypts password only. TACACS+ Port 49/TCP — encrypts everything. "Which is more secure?" → TACACS+. Always.
Afternoon: A courier tosses a tiny package through Door 69 — no questions, no receipt. That's TFTP. Staff pass spreadsheets through Door 445 — SMB. Gary monitors the espresso machine via Door 161 (SNMP). When the fridge alarm goes off, it buzzes through Door 162 — an SNMP trap. Every door posts its log through Door 514 — Syslog. Gary's IT mate logs in remotely through Door 3389 — RDP.
TFTP Port 69/UDP. SMB Port 445. SNMP Port 161/UDP, traps Port 162/UDP. Syslog Port 514/UDP. RDP Port 3389.