Private IP & Bogon Address Checker
Check IPv4 or IPv6 against a dated local snapshot of the complete IANA special-purpose registries, with flags, source and longest-prefix matches.
About this private ip & bogon address checker
Check IPv4 or IPv6 against a dated local snapshot of the complete IANA special-purpose registries, with flags, source and longest-prefix matches Performs protocol inspection, IP calculation, and network analysis client-side without sending probes or exposing network topology.
Protocol mechanics & network logic
The execution engine processes input tokens and applies transformations in the browser sandbox. Specifically, Enter one IPv4 or IPv6 address and run locally. Read classification, prefix, range, flags, rawFlags, qualifiers, assignmentStatus, terminationDate, rfc and registry. The five flags describe source, destination, forwarding, global reachability and protocol reservation; true/false/null preserve the registry values. Null means unspecified or not applicable. Read qualifiers alongside flags. For active registry matches, bogon is true only when globallyReachable is false; terminated entries return bogon false.
Worked network diagnostic scenario
Scenario: Inspect the IANA documentation allocation for 192.0.2.1.
Sample input:
Processing: Match 192.0.2.1 to the longest IANA prefix 192.0.2.0/24; read Documentation (TEST-NET-1), RFC 5737 and the false global-reachability flag.
Illustrative output:
Addressing limits & protocol boundaries
Accepts canonical dotted IPv4 and full or compressed IPv6 with an optional final dotted IPv4 suffix. Rejects CIDR suffixes, zone IDs and brackets. No live network requests. Special-purpose does not mean blocked; a registry globallyReachable flag does not prove live connectivity. A miss (inconclusive-no-match, bogon false, range null), invalid input, null global flag or terminated assignment is inconclusive for current reachability. This snapshot is not an allocation inventory or a complete unallocated/bogon feed. Multicast is not ordinary unicast.
Addressing calculations and subnet models in Private IP & Bogon Address Checker follow IETF RFC definitions. Ensure subnet masks and CIDR prefixes match your network topology.
Offline network inspection boundary
Address parsing and CIDR calculations in Private IP & Bogon Address Checker run entirely client-side without probing external IP networks or transmitting routing data.
IETF RFC specifications & IANA registries
IETF Request for Comments (RFC) standards and IANA registry references:
- IANA IPv4 Special-Purpose Address Registry (snapshot updated 2025-10-09; https://www.iana.org/assignments/iana-ipv4-special-registry/)
- IANA IPv6 Special-Purpose Address Registry (snapshot updated 2025-10-09; https://www.iana.org/assignments/iana-ipv6-special-registry/)
- RFC 6890 (Special-Purpose IP Address Registries)
- RFC 1112 and RFC 4291 (supplemental multicast)
Private IP & Bogon Address Checker verification · Audit standards
How to use it
- Enter an IPv4 address or an IPv6 address such as 2001:db8::1.
- Review parameter fields, units, or options configured for Private IP & Bogon Address Checker.
- Click the action button or observe immediate live calculations rendered by Private IP & Bogon Address Checker.
Frequently asked questions
How does the checker classify an address?+
IANA registry snapshot: 2025-10-09, retrieved 2026-10-04. All 25 IPv4 rows (26 prefixes) and 25 IPv6 rows (25 prefixes) are included. The longest prefix wins, including specific exceptions. Multicast 224.0.0.0/4 and ff00::/8 is classified separately from the registry.
What do the flags and result fields mean?+
Enter one IPv4 or IPv6 address and run locally.
Does a result prove current public reachability?+
No live network requests. Invalid IPv4 address format or Invalid IPv6 address format means syntax was rejected (valid false); bogon false on invalid input does not identify a public address.
Can I check a known registry entry?+
Security isolation for "Can I check a known registry entry?" ensures zero transmission beyond your local workstation.