Quick reference
| Setting | Value / behavior |
|---|---|
| /24 | 256 total / 254 traditional hosts |
| /31 | 2 point-to-point addresses |
| /32 | one host route |
How to use the result
CIDR notation combines a dotted IPv4 address with a prefix length from 0 to 32. The prefix counts network bits; the remaining bits identify addresses within that network. This tool performs unsigned 32-bit masking to obtain the network address, then sets the host bits to find the last address. A /24 contains 256 addresses, while a /16 contains 65,536. An input host does not need to be the first address: 192.168.1.42/24 correctly maps to 192.168.1.0/24.
Limits and interpretation
For traditional prefixes through /30, the displayed usable range excludes the network and broadcast addresses. For /31, the tool follows the RFC 3021 point-to-point interpretation with both addresses usable. A /32 represents a single host route. These interpretations do not prove that a cloud provider or network appliance permits every address: providers can reserve additional addresses, and point-to-point assumptions may not apply to a general LAN. IPv6, routing reachability and firewall behavior are outside this calculator’s scope.
Check against your destination
Run the supplied example first, then replace it with a representative input from your own workflow. Change one parameter at a time so the effect is easy to inspect. Copy or download the output and compare it with a small known case before using it in a larger system. A successful calculation establishes only the behavior described on this page; it cannot check the assumptions or access rules of a remote application. Errors are shown next to the workspace rather than silently returning an empty success.
Local processing and data handling
This tool runs in the browser and does not transmit the entered content to a processing service. No input is saved to local storage, added to the URL or synchronized to an account. The clear control removes the current field and displayed result from this page. Clipboard contents and downloaded files remain under your operating system’s control. Keep original inputs when exact byte preservation matters, and avoid including sensitive tokens or private text in screenshots that you later share.
Frequently asked questions
Does the tool contact my server?
No. It processes the provided input locally and does not execute commands on your systems.
Can I download the result?
Yes. Use the Download result control after a successful run.
What happens to my input?
It remains in this page until cleared or closed. It is not saved by the tool.
About this tool
Built and maintained by Mihai at Void Fabric. This page documents the behavior of the current implementation. Found an error or an unclear assumption? Send a reproducible example with sensitive values removed.
Reference: Void Fabric field notes · Testing and editorial policy