Queries our registry database on demand, only when you submit. Nothing runs automatically.
Frequently Asked Questions
What is a BGP prefix?
A prefix (written as an IP range plus a slash and a number, like 45.66.219.0/24) is a block of IP addresses announced as a single unit on the internet via BGP. It's the same "IP range" you'd see listed under an ASN's announced routes.
How is this different from the IP WHOIS Lookup tool?
IP WHOIS Lookup takes a single IP address and finds whatever range covers it. This tool takes the range itself directly (in CIDR notation), which is what you already have when you're looking at an ASN's or a WHOIS record's list of announced routes.
Can I export the individual IP addresses in a range?
Yes, use the Export button under "IP Addresses in This Range" to download the bare address list as CSV, JSON, or plain text, computed entirely in your browser. It's just the addresses themselves: this tool is backed by WHOIS and routing registry data, which never tracks live per-address details like hostnames or reachability. Ranges larger than 65,536 addresses aren't offered, since enumerating them client-side isn't practical.
Does this cover prefixes outside Europe?
Yes. This tool covers prefixes registered under all five regional internet registries: AFRINIC, APNIC, ARIN, LACNIC, and RIPE NCC, not just Europe.
Looking up a single IP address instead?
Try the IP WHOIS Lookup Tool