← Courses
IND 510 · 2 credits
Course Outline
How the Internet Works
How the internet actually works, from the moment you type a URL to the response rendering on screen. You will learn IP addresses, ports, DNS, packets, TCP, raw HTTP, curl, cookies and sessions, HTTPS and certificates, caching and CDNs, and finish with a practical checklist for debugging any connection.
What you will learn
- ✓Trace the full journey of a web request, from URL to rendered response
- ✓Explain IP addresses, ports, and DNS, and inspect them with dig and nslookup
- ✓Read and write raw HTTP requests and responses, and drive APIs with curl
- ✓Describe how cookies and sessions keep a user logged in across requests
- ✓Explain what TLS certificates prove and what HTTPS protects you from
- ✓Debug a broken connection layer by layer with a repeatable checklist
Course outline
Unit 1The Big Picture
- 1-1Clients, servers, and messages2 checks · 8 min
- 1-2What happens when you type a URL3 checks · 12 min
Unit 2Addresses and Names
- 2-1IP addresses4 checks · 10 min
- 2-2Ports: many doors on one machine3 checks · 9 min
- 2-3DNS: how names become addresses3 checks · 12 min
Unit 3Reliable Delivery: Packets, TCP, and UDP
- 3-1Packets: data travels in pieces3 checks · 10 min
- 3-2TCP and the three-way handshake3 checks · 11 min
- 3-3UDP vs TCP: choosing your delivery4 checks · 8 min
- 3-4Latency, bandwidth, and round trips4 checks · 11 min
Unit 4HTTP I: Requests and Responses
- 4-1Anatomy of an HTTP request4 checks · 11 min
- 4-2Anatomy of an HTTP response3 checks · 10 min
- 4-3Methods and status codes4 checks · 10 min
- 4-4APIs: HTTP for programs4 checks · 11 min
Unit 5HTTP II: Driving the Web with curl
- 5-1Meet curl2 checks · 10 min
- 5-2Query parameters and URL encoding3 checks · 10 min
- 5-3POSTing data and JSON APIs3 checks · 12 min
- 5-4Redirects: when the answer is "look elsewhere"3 checks · 10 min
Unit 6Cookies, Sessions, and State
- 6-1Cookies: HTTP has no memory4 checks · 10 min
- 6-2Sessions: how login stays logged in3 checks · 9 min
Unit 7HTTPS and TLS: Locking the Conversation
- 7-1What encryption buys you4 checks · 11 min
- 7-2Certificates: proving who you are talking to2 checks · 10 min
Unit 8Caching and CDNs: Why Fast Sites Are Fast
- 8-1Cache headers: permission to remember4 checks · 11 min
- 8-2CDNs: moving the content closer3 checks · 9 min
Unit 9Capstone: Debugging Connectivity
- 9-1The connectivity checklist2 checks · 12 min
- 9-2Capstone: run the diagnosis5 checks · 13 min
Practice while you learn
Use Hack University's public online code editor when you want to run code online before committing to the full curriculum. The browser compilers are free for quick syntax checks, exercises, and interview practice in an isolated sandbox environment.