Where does this address belong?
A prefix tells us which bits identify an IPv4 network and which bits remain for addresses inside it.
In 30 seconds
- A /24 block contains 256 addresses; a /25 contains 128.
- Ordinary subnets reserve a network and broadcast address.
- A /31 point-to-point link and a /32 host route are special cases.
Make it concrete
192.168.10.42/24 belongs to 192.168.10.0/24. Try /25 in the lab and see which boundary changes.
- 0132 bits
- 02Network prefix
- 03Host portion
Check your understanding
Does /25 contain fewer addresses than /24?
- A /24 block contains 256 addresses; a /25 contains 128.
- Ordinary subnets reserve a network and broadcast address.
- A /31 point-to-point link and a /32 host route are special cases.
Go to the source
Sources reviewed: 13.09.2026