Every network on the internet belongs to an autonomous system. Enter an AS number to see who runs it, where it operates and which IP ranges it announces.
Enter a valid AS number, e.g. AS13335 or 13335.
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An Autonomous System Number identifies a network that manages its own routing on the internet — an ISP, a cloud provider, a university or a large enterprise. There are over 100,000 active ASNs; the routing tables that connect them are what makes the internet a single network.
Knowing the ASN behind an IP tells you instantly whether traffic comes from a residential provider, a datacenter or a mobile carrier. Fraud teams block datacenter ASNs on signup forms, CDNs route by ASN, and security teams use it to attribute scanning activity to hosting providers.
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