BurrowGate ASN Lists

Open ASN lists for best-effort network traffic classification. They are designed for BurrowGate but use a simple text format that any firewall, proxy, analytics system, or application can consume.

Every ASN present in the local GeoLite2 ASN database is sorted into exactly one broad category (lists/all.txt is their union). lists/ is entirely generated output, rebuilt from scratch on every run by scripts/generate-lists.mjs: it matches each organization name against an ordered set of keyword rules, applies manual corrections from scripts/overrides.txt, and puts anything that matches neither in lists/unknown.txt for review. Because a correction lives in the script's own inputs and never in lists/ itself, it survives being regenerated against an updated mmdb.

lists/ is gitignored, not committed - it's built locally and published to a CDN. See Downloading.

These lists are policy signals, not proof that a visitor is malicious or that every address announced by an ASN has the same purpose. Start with identification or monitoring, review your own traffic, and maintain explicit ASN or IP allowlists for trusted networks.

Repository layout

.
├── lists/                      (generated, gitignored - see Downloading)
│   ├── all.txt
│   ├── manifest.json
│   ├── vpn.txt
│   ├── proxy.txt
│   ├── satellite.txt
│   ├── mobile-carrier.txt
│   ├── education.txt
│   ├── government.txt
│   ├── healthcare.txt
│   ├── financial.txt
│   ├── gaming.txt
│   ├── media-broadcasting.txt
│   ├── nonprofit-religious.txt
│   ├── transportation.txt
│   ├── utility.txt
│   ├── datacenter.txt
│   ├── isp-telecom.txt
│   └── unknown.txt
├── scripts/
│   ├── generate-lists.mjs
│   └── overrides.txt
├── tests/
│   └── validate.mjs
├── CONTRIBUTING.md
├── LICENSE
└── README.md

Available lists

List	Meaning
all.txt	Every unique ASN included by the repository.
vpn.txt	VPN providers or VPN services.
proxy.txt	Public or commercial proxy services.
satellite.txt	Satellite internet access providers.
mobile-carrier.txt	Cellular and mobile network operators.
education.txt	Universities, schools, and other educational institutions.
government.txt	Government agencies, public administration, and military networks.
healthcare.txt	Hospitals, clinics, and other healthcare organizations.
financial.txt	Banks, insurers, and other financial institutions.
gaming.txt	Video game publishers, platforms, and esports organizations.
media-broadcasting.txt	Television, radio, news, and other media organizations.
nonprofit-religious.txt	Charities, foundations, NGOs, and religious organizations.
transportation.txt	Airlines, airports, railways, shipping, and other transportation operators.
utility.txt	Electric, water, gas, and other energy or utility providers.
datacenter.txt	Datacenter, cloud, CDN, or hosting infrastructure.
isp-telecom.txt	Fixed-line internet service providers and telecommunications operators.
unknown.txt	Not confidently classified from the organization name alone; needs manual review.

manifest.json provides a generatedAt timestamp plus stable category IDs, labels, descriptions, filenames, and row counts. Consumers can use it to discover categories instead of hard-coding the current set.

Every ASN in all.txt appears in exactly one category file, the categories partition all.txt, they don't overlap.

File format

Every non-empty line contains the decimal ASN followed by at least one space and its organization name:

211252 Delis LLC
398324 Censys, Inc.

The ASN has no AS prefix. Files are UTF-8, deduplicated, and sorted numerically by ASN. Consumers should treat the first whitespace-delimited field as the identifier and the remainder as informational organization text.

An ASN that the local GeoLite2 database doesn't have an organization name for is retained as Unknown organization so maintainers can research and correct it without losing the classification.

Classification methodology and limitations

This is a best-effort, largely unreviewed heuristic classification, not a hand-audited dataset. An organization's registered legal name is a weak signal:

• Brand names that don't describe the business (e.g. a mobile carrier with no "mobile" in its legal name) are missed and land in unknown.txt.
• Keyword rules can misfire on unusual names.
• Roughly two-thirds of all ASNs currently sit in unknown.txt because most small operators register under a generic legal name (a person's name, or a bare "X LLC"/"X GmbH") with no descriptive keyword at all.
• ASN ownership, routing, and business models change over time, and one ASN can host consumer, business, VPN, proxy, and unrelated traffic simultaneously.
• Organization names identify the registered network operator and may differ from a consumer-facing brand or service.
• These files classify ASNs, not IP addresses. Consumers need a current IP-to-ASN database or service before performing a lookup.

scripts/overrides.txt should stay small and rule-driven classification should stay the default. It holds hand-verified exceptions the rules genuinely can't infer from the organization name (e.g. a VPN provider operating under an unrelated-looking shell/holding company name) - not a bulk import of some other classification. If a correction would apply to more than one ASN, prefer a new or adjusted rule in scripts/generate-lists.mjs over adding each ASN to the override file - a rule applies to the whole database and to ASNs that don't exist yet, an override only ever fixes the one ASN it names. If you import a classification from elsewhere, verify it actually fits the current categories before trusting it - a category from a different scheme (e.g. a coarser "everything that isn't X" bucket) will not line up with these definitions.

Verify before relying on any list here for anything but coarse, reversible filtering. Blocking an entire ASN can affect legitimate users - identification, logging, rate limits, or challenges are usually safer defaults than immediate blocking. See CONTRIBUTING.md for how to correct or improve a classification.

Downloading

Published to:

https://cdn.rabbit-company.com/burrowgate/asn-lists/manifest.json
https://cdn.rabbit-company.com/burrowgate/asn-lists/vpn.txt
https://cdn.rabbit-company.com/burrowgate/asn-lists/datacenter.txt

Example JavaScript loader:

async function loadAsns(url) {
	const response = await fetch(url);
	if (!response.ok) throw new Error(`ASN list returned HTTP ${response.status}`);

	return new Map(
		(await response.text())
			.split(/\r?\n/)
			.filter(Boolean)
			.map((line) => {
				const separator = line.indexOf(" ");
				return [Number(line.slice(0, separator)), line.slice(separator + 1)];
			}),
	);
}

const vpnAsns = await loadAsns("https://cdn.rabbit-company.com/burrowgate/asn-lists/vpn.txt");

Regenerating and manual maintenance

Everything under lists/ (including lists/manifest.json) is generated output. Never hand-edit it - scripts/generate-lists.mjs fully rewrites every file in lists/ on each run, so a direct edit there is silently discarded the next time someone regenerates. All maintenance happens one level up, in the generator's own inputs:

• scripts/generate-lists.mjs - the keyword rules that assign a category from the organization name, and the categories list itself.
• scripts/overrides.txt - a flat <ASN> <category-id> file of manual corrections that take priority over the rules. This is the durable home for anything that isn't (or shouldn't be) inferable from the org name alone - most commonly, moving an ASN out of unknown.txt after research.

Because corrections live there instead of in lists/, they survive being regenerated against a newer local/GeoLite2-ASN.mmdb - a re-run reclassifies only ASNs that are new to that override file and every rule.

local/GeoLite2-ASN.mmdb is gitignored (see .gitignore) and must be supplied locally to regenerate:

npm install
npm run generate:lists

This rewrites every file in lists/, including manifest.json with a fresh generatedAt timestamp, even if nothing else changed.

To correct a specific ASN, add a line to scripts/overrides.txt (<ASN> <category-id>, one per line, # comments allowed) or, for a one-off fix, an entry in the inlineOverrides object near the top of scripts/generate-lists.mjs. Then regenerate and validate:

npm run generate:lists
node tests/validate.mjs

See CONTRIBUTING.md for classification and review guidance.

Adding a category

Add an entry to categories and a matching pattern to rules in scripts/generate-lists.mjs, then regenerate and validate. Document the new category in the table above too. Category IDs should be stable lowercase names separated by hyphens. Describe an observable network or service type and avoid implying that every request from the network is harmful.

License

The repository is available under the MIT License. Contributions must only include information that can be redistributed under compatible terms.