Networking – How to find out all IP ranges belonging to a certain AS


I want to know what IP ranges are belonging for example to the AS714.

How do I get this information?

I know how to do the reverse way, which is easy with whois. But the other way doesn't seem to be that easy.

Best Answer

They're listed online with related details at (replace the ASN to get the equivalent details for any other ASN).

If instead of browsing them you'd rather grab them programmatically you can use the RADb whois server:

$ whois -h -- '-i origin AS714' | grep -Eo "([0-9.]+){4}/[0-9]+" | head
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