ASN lookup
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Example network searches
Find an ASN by number, IP, prefix or network name. Browse and copy its prefixes.
Frequently asked questions
An AS number (AS13335 or 13335), an IP address, a CIDR range, or part of a network name such as Cloudflare. The type is detected automatically; you can also choose it in the lookup options.
For each ASN: its number, its name and its IPv4 and IPv6 prefixes, ready to copy. From an IP address you get the prefixes that contain it; from a range, the ones that overlap it.
Yes: “Search hosts” on an ASN opens a host search on that AS number. For a single address, IP lookup shows the services, names and certificates observed on it.
1 credit per lookup, even when nothing matches.