STUDY

Networking Lab

Learn how computer networks really work by fixing them. Twenty lessons – layers, MAC and IP addresses, ARP, TCP, UDP and ports, NAT, private ranges, IPv6, subnet masks, subnetting step by step, sizing and summarising, the default gateway, switches, VLANs, loops and spanning tree, Wi-Fi, routers and routing tables, the way back, DHCP and DNS, firewalls, everyday commands and a method for finding faults. Then twelve lab networks, each with a classic fault – a wrong gateway, a wrong mask, an unplugged cable, a missing return route, a routing loop, a wrong next hop, a stray longer prefix, three sites, a /31 link, a new laptop to set up – and a subnetting practice with new questions every time. Use ping, tracert, show, a subnet calculator and commands to change settings, and watch each packet step by step: ARP broadcasts, switches learning MAC addresses, routers lowering the TTL. The packets are moved by our own engine written in C++ and running as WebAssembly.

Ready to try · Learn how computer networks really work by fixing them. Twenty lessons – layers, MAC and IP addresses, ARP, TCP, UDP and ports, NAT, private ranges, IPv6, subnet masks, subnetting step by step, sizing and summarising, the default gateway, switches, VLANs, loops and spanning tree, Wi-Fi, routers and routing tables, the way back, DHCP and DNS, firewalls, everyday commands and a method for finding faults. Then twelve lab networks, each with a classic fault – a wrong gateway, a wrong mask, an unplugged cable, a missing return route, a routing loop, a wrong next hop, a stray longer prefix, three sites, a /31 link, a new laptop to set up – and a subnetting practice with new questions every time. Use ping, tracert, show, a subnet calculator and commands to change settings, and watch each packet step by step: ARP broadcasts, switches learning MAC addresses, routers lowering the TTL. The packets are moved by our own engine written in C++ and running as WebAssembly.