ASN Lookup

What It Does

Identifies the Autonomous System Number (ASN) responsible for routing traffic for an IP address. Returns the AS number, AS name (e.g., CLOUDFLARENET), organization (e.g., Cloudflare, Inc.), registration country, network type classification (ISP, hosting provider, enterprise, education, or government), `type_source` so callers know whether the type came from a curated list or was inferred from the AS description, and the prefix's RPKI ROA validity (valid / invalid_asn / invalid_length / unknown) — the canonical signal for detecting BGP hijacks. Cloudflare edge-level ASN data is supplemented with a curated database of major global networks plus a Team Cymru fallback that covers every allocated AS.

Why It's Useful

ASN data reveals the organization behind an IP address, which is more reliable than reverse DNS or WHOIS. It's essential for threat intelligence enrichment, abuse reporting, traffic segmentation, and understanding whether visitors come from residential ISPs, cloud hosting, or enterprise networks. Network type classification helps distinguish legitimate users from potential automated threats originating from hosting infrastructure. RPKI status flags prefixes that are being announced by an unauthorized AS — the bedrock signal for BGP hijack and route-leak detection (RFC 6811).

Use Cases

Parameters

Response Fields

Code Examples

curl "https://api.edgedns.dev/v1/network/asn" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d "ip=8.8.8.8"

const response = await fetch(
  'https://api.edgedns.dev/v1/network/asn?ip=8.8.8.8',
  {
    headers: {
      'Authorization': 'Bearer YOUR_API_KEY'
    }
  }
);

const data = await response.json();
console.log(data);

import requests

response = requests.get(
    'https://api.edgedns.dev/v1/network/asn',
    headers={'Authorization': 'Bearer YOUR_API_KEY'},
    params={
    'ip': '8.8.8.8'
    }
)

data = response.json()
print(data)

Related Endpoints

External References

Learn more about the standards and protocols behind this endpoint.