Intro

IP2Location is glad to announce the introduction of new Autonomous System data in both the IP2Location DB26 database and the IP2Location.io API. In the DB26, previously the data included the Autonomous System (AS) name and Autonomous System Number (ASN). Starting in September 2025, existing & new DB26 users can have access to more AS data like AS domain name, AS CIDR and the AS usage type. At the same time, the IP2Location.io API users with a Security Plan subscription will have access to similar data which will be grouped under the as_info section of the JSON result.

What is an Autonomous System (AS)?

An Autonomous System (AS) is a collection of IP address ranges (prefixes/CIDRs) that are all managed by the same network operator (like an ISP, cloud provider, university, or enterprise). Think of it as a large network under one administration, with its own routing policies.

What is an Autonomous System Number (ASN)?

An ASN is the unique number assigned to each AS. It identifies that network on the Internet.

Example:

Google → 15169

Cloudflare → 13335

Mullvad VPN → 197922

Why do ASNs exist?

The Internet is made of tens of thousands of ASes. They exchange routes using BGP (Border Gateway Protocol).

ASN tells routers:

“This IP range belongs to ASXXXX, and here’s how to reach it.”

Common Uses for the AS data

Security & Threat Intelligence

Using the AS data, you can identify the organization behind the IP. E.g., If you look up an IP and see it belongs to AS15169, you immediately know that’s Google, based on the AS domain value. This is more reliable than just “WHOIS contact”, because the ASN is what’s actually being routed.

In addition, the AS usage type can reveal possible proxy users. When you see “DCH” in the AS usage type, that means it is a data center. When a user uses a proxy to visit a website, it usually means they are up to no good and should be blocked if they are making a purchase or conducting sensitive transactions.

Being able to block all traffic from data center or hosting ASNs (common for VPNs, scrapers & bots), you can rest easy about malicious actors trying to breach your system or steal your data. These bad actors often rely on certain ASNs or CIDRs as they belong to cheap hosts or bulletproof providers.

Having the AS CIDR is very useful whenever you’re trying to block Distributed Denial of Service (DDoS) attacks. You can easily input the CIDR into firewalls and other security applications to mitigate attacks.

Network Optimization

If you run an online service, you can filter routes or prioritize traffic differently depending on ASN (e.g., optimize for users on residential ISPs).

Fraud Screening

ASN data is often used as part of an online order fraud screening process. The IP address used by the customer can be linked to the ASN and used to perform geolocation checks. E.g., a user claims to be in Malaysia, but their IP belongs to AWS ASN in Singapore, that’s suspicious.

Similarly, if the AS usage type is “DCH” which is a data center, but the user pretends to be a home shopper, flag that order for manual review.

Conclusion

There are many ways to use Autonomous System data and with the addition of the AS CIDR, AS usage type and AS domain name, we are confident that users will be able to fully leverage them to further mitigate attacks and keep fraud to a minimum. Get your latest DB26 database today or subscribe to the IP2Location.io API with the Security Plan.

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