What is a subnet?
In one sentence: A group of addresses that count as one neighbourhood, like every 192.168.1.something at home; devices in it talk directly.
A little more
A subnet is a group of IP addresses that belong together, like all the houses on one street. At home it is usually every address that starts 192.168.1 (or 192.168.0, or 10.0.0): the first part names the street and the last number is the house.
A setting called the subnet mask, often 255.255.255.0, tells each device how much of an address is the street. Devices on the same street send messages straight to each other; anything for a different street goes to the gateway. That is why two routers making two different streets at home can stop a laptop from finding the printer.
See it in action
- 1What happens when you open a web page?Follow one click from your keyboard to a server and back: DNS, the padlock handshake, HTTP, tunnels and painting the page.6 min · interactive
- 7Why does Wi-Fi get weaker through walls?Build a little house, drag the router around and watch the Wi-Fi signal spread room by room.7 min · interactive
Do it for real
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