Computer Networking · Interactive Lesson

Simple Web Page Requestwww.google.com

Plug a laptop into the school network and load a webpage. Four protocols have to run, in order — DHCP, ARP, DNS, then TCP + HTTP — step through every packet and watch how each message is wrapped, layer by layer.

Network map · what the laptop knowsIP: none
SCHOOL NETWORK INTERNET LAPTOP 08:00:27:97:91:D1 no IP yet SWITCH learns MACs GATEWAY IP: ? MAC: ? ISP ROUTER provider network DNS SERVER IP: ? WEB SERVER www.google.com IP: ?
Current step
tip: use ← → keys
Encapsulationlayers 5 → 1
5Application
4Transport
3Network
1Physical
Packet capturetcpdump -i eth0

Based on Computer Networking: A Top-Down Approach (6th ed.), Kurose & Ross · Original notes: Grégoire Roumache, November 2019