01
CIDR details
Type a CIDR prefix. Get the mask, network and broadcast addresses, the first and last hosts, and the host count.
examples:
10.0.0.0/24
192.168.1.128/26
172.16.0.0/12
10.0.0.0/31
02
Equal split
Split a parent prefix into N equal subnets. N must be a power of two. The result is a numbered list of child prefixes with their usable host counts. Capped at 256 — larger splits are better generated with a script than reviewed in a table.
03
Find next available
Given a parent prefix, a target CIDR, and a list of already-used subnets, find the next available block of the target size inside the parent. Also flags overlaps in the used list.