Step 4
Computer Networks
How a message gets from one computer to another: layers, IP, TCP, HTTP and DNS. Web, mobile, cloud and security work all rely on it.
Know these firstOperating Systems
- Video course
- Video course: Kurose & Ross video dersleri
- Layered architecture
- HTTP and DNS
- TCP and UDP
- IP and routing
- Subnets
- Link layer
- Network security basics
Why it matters
When you type an address into a browser, a DNS lookup, a TCP connection, a TLS handshake and an HTTP request happen behind it. A slow site, a mobile app that cannot connect or a port left open: you need this course to understand any of them.
What to know
- The layered model: application, transport, network and link layers and what each does.
- HTTP, DNS and the end-to-end journey of a web request.
- TCP versus UDP; reliable delivery, flow and congestion control.
- IP addresses, subnets, NAT and routing.
- Ethernet, MAC addresses, ARP.
- TLS and basic network security.
Practice and projects
- Watch your own traffic in Wireshark; find the packets of one web request.
- Write a small chat program with TCP sockets.
- Use ping, traceroute, nslookup and curl and read their output.
Common mistakes
- Memorizing the layers without being able to walk through a request end to end.
- Going into the exam without practicing subnet calculations.