Each autonomous system (AS) is assigned a unique autonomous system number (ASN). These numbers are managed globally by Regional Internet Registries (RIRs) under the authority of the Internet Assigned Numbers Authority (IANA).
What is an autonomous system (AS)?
An autonomous system (AS) is a group of networks or subnets that operates under a single, common routing policy. They communicate with each other using the Border Gateway Protocol (BGP). In Edge Security Acceleration (ESA) rules, you can use the unique number assigned to an AS to identify and distinguish different network providers or geographic regions. ESA uses this information to intelligently manage traffic based on its network source, optimizing performance, security, and user experience.
What is an autonomous system number (ASN)?
An autonomous system number (ASN) is a unique 32-bit integer that identifies an autonomous system. The Border Gateway Protocol (BGP) uses ASNs to distinguish different networks or network providers. Within ESA, an ASN acts as an identifier to match and manage traffic from a specific network or geographic region.
The five Regional Internet Registries (RIRs) manage ASNs within their respective regions.
Find the ASN for an IP address
Use a Regional Internet Registry (RIR)
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Go to the website of an RIR, such as APNIC Whois Search.
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Enter the IP address in the search box and click Search. The corresponding ASN is displayed.
Find the organization information for an ASN
Use a Regional Internet Registry (RIR)
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Go to the website of an RIR, such as APNIC Whois Search.
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Enter the ASN in the search box and click Search. The organization information for the ASN is displayed.
Use the DNSChecker tool
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Enter the ASN in the search box and click Lookup ASN. The organization information for the ASN is displayed.
Find a list of all ASNs
You can find a complete list of ASNs on the official IANA website.