ASN Lookup
Search for Autonomous System Numbers (ASN) to find organization details, registration dates, and network information.
What is an Autonomous System (AS)?
An Autonomous System (AS) is a collection of connected Internet Protocol (IP) routing prefixes under the control of one or more network operators on behalf of a single administrative entity or domain that presents a common, clearly defined routing policy to the internet.
Each AS is assigned a unique Autonomous System Number (ASN) for use in BGP (Border Gateway Protocol) routing. Major ISPs, large tech companies, and universities typically have their own ASNs.
Frequently Asked Questions
What is an ASN (Autonomous System Number)?
An Autonomous System Number (ASN) is a unique identifier assigned to an Autonomous System (AS) for use in BGP routing. It allows networks to exchange routing information on the internet.
How do I lookup an ASN?
Enter the ASN number (with or without 'AS' prefix) in the search box above. Our tool will query multiple WHOIS registries to find organization details, registration dates, and announced IP prefixes.
What information can I find about an ASN?
You can find the organization name, country, registration date, last update date, and a list of IP prefixes (network blocks) announced by that ASN.