ASN Lookup
Look up an Autonomous System Number or public IP address and review the ASN, organization, registry status, registration date, or IP network context returned by the live lookup providers.
Use this ASN Lookup tool to check network registration context for an Autonomous System Number or a public IP address. Enter a value such as AS15169, 15169, or 8.8.8.8, then review the ASN, organization, status, registration date, or IP network fields returned by the live lookup path.
What ASN Lookup Is For
An Autonomous System Number, often written as an ASN or AS number, identifies a network that participates in interdomain routing. Network operators, hosting providers, cloud platforms, access providers, universities, content delivery networks, and large enterprises use ASNs to announce routes and exchange traffic with other networks. Looking up an ASN can help you understand which organization is associated with a routed network, whether a known AS number is active in registry data, or what network context an IP geolocation provider currently associates with an address.
This Digital Domain Kit tool is built for quick operational checks. It does not replace a full routing analysis platform, registry portal, abuse desk workflow, or historical BGP database. Its value is speed: type a numeric ASN, an AS-prefixed ASN, or a public IP address, and the page displays the fields the production component can verify through its configured external lookup services.
How To Use The Tool
- Enter an ASN or public IP address in the ASN / IP Address field. Examples include
AS15169,15169, and8.8.8.8. - Use a single value only. The current interface does not accept batches, CIDR ranges, organization names, domains, or pasted routing tables.
- Click the Lookup button and wait while the server queries the configured registry or IP lookup service.
- For ASN input, review the AS number, type, organization, status, and registration date when ARIN RDAP returns a record.
- For IP input, review the AS field, organization, country, city, ISP, timezone, and address context when the IP lookup provider returns them.
- Use Clear to reset the visible input before checking another network value.
Inputs, Outputs, And Limitations
The production implementation trims the submitted text and checks whether it is a valid IP address. If it is an IP address, the component sends the address to ip-api.com's JSON endpoint with a limited field list. If the value is not an IP address, the component accepts either a numeric ASN or an AS-prefixed number, strips the leading AS for the query, and asks ARIN RDAP for /registry/autnum/{number}. If ARIN does not return a successful ASN response, the component attempts a fallback request to ipapi.co's ASN endpoint.
| Area | Verified Behavior | Important Limitation |
|---|---|---|
| ASN input | Accepts a bare number such as 15169 or an AS-prefixed value such as AS15169. | Text names, comma-separated lists, AS-SET names, and route objects are not supported inputs. |
| ASN normalization | The live component normalizes matching values to a single AS prefix for display. | The display value is normalized text, not a guarantee that every upstream source uses the same handle format. |
| ASN source path | Numeric ASN lookups first use ARIN RDAP autnum data; failed ARIN responses may fall back to ipapi.co. | ARIN is not the only Regional Internet Registry, so non-ARIN numbers can depend on fallback availability and coverage. |
| IP input | Valid IP addresses use ip-api.com and can return ASN, organization, ISP, country, city, timezone, latitude, and longitude fields. | IP geolocation and organization fields are lookup hints. They can be approximate, cached, incomplete, or different from live routing. |
| Output fields | ASN results can show type, AS number, organization, status, and registration date. IP results can show type, AS string, organization, country, city, ISP, and timezone. | The page does not show route prefixes from BGP, RPKI validity, peering, upstreams, downstreams, abuse contacts, WHOIS remarks, or history. |
| Error handling | Unsupported text returns a validation-style message asking for a valid IP address or AS number. | Service timeouts, provider rate limits, missing records, and temporary upstream errors may produce a generic failure message. |
Verified Examples
On September 16, 2026, the production component was tested directly with the live lookup method. The repair for duplicate AS prefixes was confirmed: both AS15169 and 15169 returned AS15169, not ASAS15169. For that ARIN RDAP result, the visible fields included type ASN, name GOOGLE, organization Google LLC, status active, and registration date 2012-02-24.
| Test Input | Verified Result Path | Key Output Observed |
|---|---|---|
AS15169 | ASN lookup through ARIN RDAP | AS15169, type ASN, organization Google LLC, status active, registration date 2012-02-24. |
15169 | ASN lookup through ARIN RDAP | AS15169, confirming the numeric and prefixed forms display the same normalized ASN. |
8.8.8.8 | IP lookup through ip-api.com | Type IP, AS field AS15169 Google LLC, organization Google Public DNS, ISP Google LLC, country United States, city Ashburn, timezone America/New_York. |
not-an-asn | Input validation | Error: Please enter a valid IP address or AS number (e.g., AS15169). |
These examples document the output format observed during the test. Registry records, provider datasets, geolocation labels, and routing announcements can change. If you are investigating a network event, preserve your own logs and record the lookup time instead of treating any single result as permanent evidence.
Understanding The Lookup Sources
For ASN input, the primary source is ARIN's RDAP autnum endpoint. RDAP is a structured registration data protocol; RFC 9083 defines JSON responses for registration data including Autonomous System number objects with members such as handle, startAutnum, endAutnum, name, status, events, and related entities. The tool displays only a small subset of what the RDAP response may contain.
For IP input, the tool uses the ip-api.com JSON endpoint with selected fields. That provider can return an as field, ISP, organization, country, city, timezone, and coordinates when available. The configured IP path is useful for quick context, but it is not a complete BGP origin lookup, and it does not prove who operated a device or account at a specific time.
If the primary ARIN ASN lookup does not succeed, the component attempts an ipapi.co ASN fallback. ipapi.co documents ASN and organization fields in its API output, but fallback coverage and response shape are outside Digital Domain Kit's direct control. Because the page depends on external services, a valid network value can still fail if a provider is unavailable, rate limited, blocking the request, or missing the record.
Responsible Use And Caveats
ASN data is helpful context, not an identity guarantee. An ASN can point to the network that registered or announces address space, but it does not identify a person, customer account, tenant, visitor, attacker, or device. Cloud hosting, VPNs, carrier-grade NAT, enterprise gateways, proxies, and shared infrastructure can all cause many unrelated users or services to appear behind the same network organization.
The city and country values returned for IP input are also approximate. They may describe a provider point of presence, routing location, registry contact region, or geolocation vendor estimate rather than a user's physical location. For access control, fraud review, abuse handling, compliance work, or security investigations, pair ASN lookup results with authenticated logs, provider records, timestamps, DNS evidence, and other corroborating sources.
Troubleshooting
| Problem | Likely Cause | What To Try |
|---|---|---|
| The page asks for a valid IP address or AS number. | The input is a name, domain, AS-SET, URL, route object, or other unsupported text. | Enter one numeric ASN such as 15169, one AS-prefixed number such as AS15169, or one IP address. |
| An ASN that exists elsewhere does not return details. | The primary ARIN path may not cover that record, and the fallback provider may be unavailable or lack the ASN data. | Try again later and compare with the appropriate Regional Internet Registry or another routing data source. |
| The IP result shows an unexpected city or organization. | Geolocation and provider mappings can reflect a network point of presence, ISP record, cloud provider, or cached vendor data. | Use the result as context only, then compare with reverse DNS, traceroute, registry data, and your own logs. |
| The AS field for an IP includes both a number and a name. | The IP lookup provider returns its as field as a combined string. | Use the AS number portion for follow-up ASN checks if you need registry-style details. |
| The lookup times out or reports a service problem. | The server could not get a usable response from the external lookup provider within the configured timeout. | Retry after a short wait. If the issue persists, use the contact link below to report the failing input. |
Related Tools
Use IP Information when you want a simpler public IP location and ISP view. Use Hostname to IP to resolve a hostname before checking the resulting address here. Use IP to Hostname to compare ASN context with reverse DNS names. Use DNS Lookup when DNS records, not routing registration data, are the primary question. Use Traceroute Online for a path-oriented network check when reachability or routing hops matter.
Technical References
The ASN path is based on RDAP-style registration data, with the production component querying ARIN's https://rdap.arin.net/registry/autnum/{asn} endpoint first. The RDAP JSON data model for Autonomous System number objects is described in RFC 9083. IP-address lookups use the ip-api.com JSON endpoint documented at ip-api.com JSON API documentation. The ASN fallback path uses ipapi.co, whose available IP and ASN-related fields are documented at ipapi.co API Reference.
Editorial Notes
This page is built and maintained by Digital Domain Kit. The technical method was last verified on September 16, 2026 by inspecting the deployed Laravel Livewire component and running production checks for AS15169, 15169, 8.8.8.8, and invalid text. The test confirmed that the previous duplicate-prefix output issue is repaired for the checked ASN inputs. To report a problem with this tool, use the contact page and include the input value, approximate lookup time, and the result or error you saw.