CIDR prefix
/28
255.255.255.240
14 usable hosts · 16 addresses
The mask for /28 is 255.255.255.240 — 16 addresses, 14 usable hosts. Very small segments — DMZs, isolated services, public-IP pools.
Mask
255.255.255.240
Wildcard
0.0.0.15
Addresses
16
Hosts
14
Worked example: 192.168.0.0/28
Network address192.168.0.0/28
Broadcast address192.168.0.15
First host192.168.0.1
Last host192.168.0.14
FAQ — /28
What is the subnet mask for /28?
The subnet mask for /28 is 255.255.255.240 (wildcard: 0.0.0.15). The first 28 bits are the network part, the remaining 4 are the host part.
How many hosts fit in a /28?
A /28 block holds 16 addresses, of which 14 are usable hosts (the network and broadcast addresses are excluded).
How many /28 subnets fit in a /24?
A /24 network divides into 16 /28 subnets.
What is a /28 used for?
Very small segments — DMZs, isolated services, public-IP pools.