/27 subnet

Mask 255.255.255.224 · 30 usable hosts · 32 addresses

/27 at a glance
Subnet mask255.255.255.224
Wildcard mask0.0.0.31
Binary mask11111111.11111111.11111111.11100000
Network / host bits27 / 5
Total addresses32
Usable hosts30
Per /8 · /16 · /24524,288 · 2,048 · 8
Example192.168.10.77/27 → network 192.168.10.64, hosts 192.168.10.65 – 192.168.10.94, broadcast 192.168.10.95

Where /27 is used

Small VLANs such as printers or management.

Block boundaries: a /27 must start at a multiple of 32 addresses, so in the last octet networks start at 0, 32, 64, 96, 128, 160, 192, 224. Calculate any specific address in the subnet calculator.

Neighbouring prefixes

← /26 (twice as large) · /28 (half the size) →

Questions

How many hosts in a /27?
32 addresses, of which 30 are usable (the first is the network address and the last is broadcast).
What is the subnet mask for /27?
255.255.255.224. In binary: 11111111.11111111.11111111.11100000. The wildcard (inverse) mask is 0.0.0.31.