ASN Lookup

Enter an Autonomous System Number (ASN) to get detailed information about it.


About ASN Lookup

An Autonomous System Number (ASN) is a unique identifier assigned to an autonomous system (AS) by the Internet Assigned Numbers Authority (IANA). An autonomous system is a collection of connected Internet Protocol (IP) routing prefixes under the control of one or more network operators that presents a common, clearly defined routing policy to the Internet.

What Information Can You Get from an ASN Lookup?

Understanding IP Prefixes

An IP prefix is a range of IP addresses that are grouped together for routing purposes. In the context of ASNs, these prefixes represent the blocks of IP addresses that an autonomous system announces to the global internet. The prefix is typically written in CIDR (Classless Inter-Domain Routing) notation, such as 192.168.0.0/24, where the number after the slash indicates how many bits of the IP address are fixed for that prefix.

Uses of ASN Lookup