/24 subnet

Mask 255.255.255.0 · 254 usable hosts · 256 addresses

/24 at a glance
Subnet mask255.255.255.0
Wildcard mask0.0.0.255
Binary mask11111111.11111111.11111111.00000000
Network / host bits24 / 8
Total addresses256
Usable hosts254
Per /8 · /16 · /2465,536 · 256 · 1
Example192.168.10.77/24 → network 192.168.10.0, hosts 192.168.10.1 – 192.168.10.254, broadcast 192.168.10.255

Where /24 is used

The default home router LAN and the most common office VLAN; also the smallest block generally accepted in BGP.

Block boundaries: a /24 must start at a multiple of 256 addresses, so in the last octet networks start at 0. Calculate any specific address in the subnet calculator.

Neighbouring prefixes

← /23 (twice as large) · /25 (half the size) →

Questions

How many hosts in a /24?
256 addresses, of which 254 are usable (the first is the network address and the last is broadcast).
What is the subnet mask for /24?
255.255.255.0. In binary: 11111111.11111111.11111111.00000000. The wildcard (inverse) mask is 0.0.0.255.