Offline ASN Directory and BGP Path Guide
Search three sourced ASN organization records locally, distinguish 16-bit and 32-bit numbers and learn special-purpose ranges and BGP path policy.
About this offline asn directory and bgp path guide
Search three sourced ASN organization records locally, distinguish 16-bit and 32-bit numbers and learn special-purpose ranges and BGP path policy Performs protocol inspection, IP calculation, and network analysis client-side without sending probes or exposing network topology.
Protocol mechanics & network logic
Enter an asplain ASN with optional AS prefix, or part of an organization or registration name. Empty input lists the three bundled records. The numeric result classifies IANA special-purpose values. The original fixed-range JSON reference remains below. BGP advertises prefixes and attributes between autonomous systems. An AS_SEQUENCE lists AS hops; an external speaker normally prepends its own ASN. A route containing the local ASN normally fails loop checks. Local policy and preference can beat a shorter AS_PATH; it is not a latency measurement. Example documentation path 64500 → 64501 → 64502 has three AS entries, with 64502 at the origin side. Repeated AS entries can reflect prepending, not extra routers.
Worked network diagnostic scenario
Scenario: Read the local reference object for ASN 64512.
Sample input:
Processing: Trim the query and return the fixed private, documentation and reserved ASN ranges. AS15169 and Google find Google LLC. AS65535 fits 16 bits and is reserved; AS65536 needs 32 bits and is for documentation.
Illustrative output:
Addressing limits & protocol boundaries
Three records only: AS15169, AS13335 and AS4134, source-checked on 2026-10-03. Numbers are decimal 0–4294967295; asdot, signed and fractional input are rejected. No match does not mean unallocated. Not-special does not establish allocation or public routability. No live BGP/RIR requests, IP-to-AS mapping, prefix counts or current peering-policy claims. Names and registrations may change.
Addressing calculations and subnet models in Offline ASN Directory and BGP Path Guide follow IETF RFC definitions. Ensure subnet masks and CIDR prefixes match your network topology.
Offline network inspection boundary
Address parsing and CIDR calculations in Offline ASN Directory and BGP Path Guide 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:
Offline ASN Directory and BGP Path Guide verification · Audit standards
How to use it
- Enter, paste, or select your input data into the Offline ASN Directory and BGP Path Guide workspace controls.
- Review parameter fields, units, or options configured for Offline ASN Directory and BGP Path Guide.
- Click the action button or observe immediate live calculations rendered by Offline ASN Directory and BGP Path Guide.
Frequently asked questions
What ranges does this guide return?+
Original shorthand helper: It returns a fixed reference object: private-use ASN ranges 64512-65534 and 4200000000-4294967294, documentation ranges 64496-64511 and 65536-65551, and reserved values 0, 23456, 65535 and 4294967295. Those literal ranges are not calculated from the entered ASN.
What does the page actually do?+
Original shorthand helper: The page has one text area, Run locally and Load sample. It trims the submitted text into query, then displays JSON containing the same fixed ranges, RFC 6996, RFC 5398 and RFC 7300, RFC 7607, RFC 6793, and a scope note. It does not establish BGP sessions, inspect routes, query an RIR, or consult a live registry.
What are its input and accuracy boundaries?+
Original shorthand helper: Any text is accepted after trimming and is only echoed as query; there is no numeric ASN parser, range membership result, RIR ownership check, route-origin lookup, prefix analysis, or current allocation data. The displayed standards are fixed reference labels, so use an authoritative current registry for an operational assignment decision.
What does the guide show for ASN 64512?+
Original shorthand helper: For 64512, it shows a fixed reference object with both private-use ranges, both documentation ranges, four reserved values, five RFC labels, and a no-live-query note. It does not establish BGP reachability, RIR freshness, or ASN ownership.