Trust through explicit semantics

Calculation methodology

NetToolsmith separates deterministic calculations from network lookups. Subnet inputs remain in your browser; public-IP and intelligence features will use clearly labeled server boundaries.

IPv4 subnet calculation

An entered address is parsed as four canonical decimal octets and combined with a prefix from/0 through /32. The network is the address AND subnet mask. The final address is the network OR wildcard mask.

Usable-address semantics

• /0–/30: network and broadcast are excluded.
• /31: both addresses are usable for RFC 3021 point-to-point links.
• /32: the single host address is usable; broadcast is not applicable.

Classification

Labels use ordered special-purpose ranges based on IANA and the relevant RFCs. “Public” means the entered address did not match one of the covered special-purpose ranges; it is not a guarantee of reachability.

Engineering review

Generated values and future vendor configuration are aids, not substitutes for review against the target platform, software release and change-control policy.