Hack the Route Start free Open app Labs / First Contact
Road 1 of 11
First Contact
Learn networking from zero: IP addresses and subnets, ARP and DHCP, routing and ICMP, and how a packet leaves its network.
Start this road, freeIP addressing & subnets
Addresses, subnet masks and cutting blocks to size.
- 01 A home network, from the laptop's point of view A home network lab: follow one laptop's traffic through it, end to end. Free
- 02 A bare machine: networking by hand Linux networking by hand: bring a bare machine online, then make it survive a reboot. Free
- 03 Addresses and subnets: on my network, or through the router? Subnetting practice: read what a prefix means, then watch a wrong one break the network. Free
- 04 VLSM: one block, subnets cut to size Cut one /24 into subnets of different sizes, so nothing is wasted. Pro
ARP & DHCP
Finding neighbours and getting an address to join.
- 01 ARP and MAC addresses: who is behind this IP address? See how ARP works: an IP address turns into a MAC address, hop by hop. Free
- 02 DHCP: how a device gets its address See how DHCP works: a device asks for an address and gets a lease. Free
- 03 DHCP relay Serve addresses to networks the DHCP server is not on, through a relay. Pro
IP routing
How packets cross routers from one network to the next.
- 01 Routing across hops: how a packet finds a server three routers away Follow routing tables and TTL across three routers, and find a broken hop. Free
- 02 Static routes, by hand Type routes by hand, then add a backup route that takes over on failure. Pro
- 03 Route summarisation: one route for many subnets Cover a branch's subnets with one route, then stop the loop it makes. Pro
ICMP & gateway redundancy
Error messages, and a gateway that survives a router.