/14 subnet (255.252.0.0)

A /14 network has 262,144 addresses, of which 262,142 can be given to hosts after the network and broadcast addresses. A very large block, typically an ISP or regional allocation, or a carved-up part of 10.0.0.0/8.

CIDR notation
/14
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255
Binary mask
11111111.11111100.00000000.00000000
Total addresses
262,144
Usable hosts
262,142
Example network
10.0.0.0/14
Example usable range
10.0.0.1 – 10.3.255.254
/24 networks in a /14
1,024

Calculate a /14 for your own address

In firewall rules and investigations

A /14 rule matches every address from 10.0.0.0 to 10.3.255.255. In Cisco ACLs the same range is written with the wildcard mask 0.3.255.255. When an alert names an IP, checking whether it falls inside a known /14 (your own network, a cloud provider’s published range or a blocked range) is often the quickest first step.