Bogon AS numbers, free with an account.
The reserved and special-use AS number ranges that should never appear in a real BGP announcement: private use, documentation, unallocated. Each range carries IANA's description of it.
Schema at a glance.
See documentation →The schema and metadata are in the docs. It is published as CSVGZ.
| start_asn | end_asn | description |
|---|---|---|
| 0 | 0 | Reserved |
| 23456 | 23456 | AS_TRANS |
| 64496 | 64511 | Reserved for use in documentation and sample code |
| 64512 | 65534 | Reserved for Private Use |
| 4200000000 | 4294967294 | Reserved for Private Use |
Downloading it from code.
Database API reference →One call gets you the current Bogon ASN build. Every official client wraps it three ways: straight to disk, a time-limited link you hand to your own runner, or bytes in memory, and checksums() returns the published digests to verify it against.
download()downloadUrl()downloadBytes()metadata()checksums()import osfrom internetdata import InternetDataclient = InternetData(os.environ["INTERNETDATA_API_KEY"])# what is in today's build, without moving the filemeta = client.database.metadata("bogon_asn_v1")client.database.download("bogon_asn_v1", "csvgz", "./bogon_asn_v1.csv.gz")sums = client.database.checksums("bogon_asn_v1", "csvgz")print(meta.updated, meta.entries, sums["sha256"])
Getting your hands on it.
Free with an account, and the file is yours: teams join Bogon ASN against the traffic, logs and routing data they already hold, inside their own infrastructure.
Routing data
Flag announcements and records that reference private, documentation-only or otherwise invalid AS numbers.
An official client for every major language.
All SDKs on GitHub →Twelve official clients for the languages you ship in, each wrapping the database endpoints: list what you're licensed for, poll a build, follow the download redirect and verify what landed. Install commands are in the docs.
What is a bogon AS number?
One reserved for private use, documentation or a special role, or not yet allocated, that should never appear in a real BGP announcement.
Where does description come from?
IANA's AS number registry, in its own words.
What is AS_TRANS?
AS 23456, which stands in for a 4-byte AS number when talking to a router that understands only 2-byte ones. It's legitimate in that role and never a real origin.
How often is it rebuilt?
Daily. The metadata call answers when the current build landed and how many rows it holds, before you fetch it.
Which formats does a build ship in?
Gzipped CSV. It's keyed by AS number, so there is no address lookup to build.
Is it really free?
Yes. Create an account and download it from the console, or with your API key from the API or any official client. It's licensed under CC BY-SA 4.0: credit InternetData and share what you build from it under the same license.
Is there a lookup API?
No. You download Bogon ASN and query it in your own systems, so nothing is metered and no address leaves them. Each build comes from the database API, or to your webhook or your own storage.
What if a row looks wrong?
Send it to us and we'll tell you what we hold on it, when we last saw it and how. Corrections land in the next build.