On Wed, 10 January 2001, Hank Nussbacher wrote:

When processing cflowd and wanting to resolve IP nets as well as ASNs as quickly as possible is there a trick to do the lookups rather than trying RIPE, ARIN, APNIC (and perhaps others) in a cyclical manner? Is there some static file that one can download that lists just the IP nets and ASN and who it belongs to (for all databases - not just ARIN)?

IANA, as the ultimate "owner" of all ASN and IPs, used to publish such a list on an irregular basis buried deep on the ISI ftp site. However I haven't seen an updated list since Jon Postel passed away.