Interactive systems and security simulation
Network Address Lab.
Step through IPv4 octets, binary masks, network addresses, broadcasts and same-subnet decisions without entering real infrastructure details.
Intended stage: GCSE core to A level recap. Prerequisites: binary place value, denary-to-binary conversion and basic network vocabulary.
What this lab covers
IPv4 addresses are written as four denary octets. A CIDR prefix such as /24 says how many of the 32 bits identify the network. A subnet mask marks those network bits. Bitwise AND keeps address bits only where the mask bit is 1, producing the network address.
- Learning outcomes: convert IPv4 octets to binary, construct subnet masks, calculate network and broadcast addresses, and decide whether two devices share a subnet.
- Privacy: calculations run locally in this browser and are reset on reload. Do not enter real school-network, public service or sensitive infrastructure addresses.
- Convention: classroom host ranges exclude the network and broadcast addresses except where /31 and /32 need a special note.
Guided walkthrough
Start a walkthrough to see the calculation steps. The default example is 192.168.1.130/24.