Module 3
IPv4 Addressing
Addresses, masks, the arithmetic people actually fail, and the single most common beginner fault - a host that can reach its neighbours but nothing beyond them.
In this module
- Split an IPv4 address into its network and host parts
- Use a subnet mask to decide whether two hosts are on the same network
- Calculate network, broadcast and usable host ranges under time pressure
- Explain what a default gateway is and what breaks without a correct one
Activities
IPv4 addresses
Four octets, 32 bits, and what the number actually identifies.
Subnet masks and prefix length
How a mask splits an address into a network and a host.
The default gateway
Where a packet goes when the destination is not local.
Knowledge check - IPv4 addressing
Same-network decisions, masks, and gateway reasoning.
Subnetting drill
Eight calculations against the clock. This is the skill people fail the exam on, and reading about it is not the same as doing it.
Lab: local works, remote doesn't
A host can ping its own subnet but nothing outside it. Find the wrong gateway and correct it.
Sign in to take the knowledge checks, run the labs and track your progress.
Curriculum topics
Each topic page lists every lesson, quiz and hands-on lab that covers it, plus how it maps onto the CCNA and Network+ blueprints.