[maxmouchet]

Another solution is to use an MMDB (“MaxMind DB”) file [1] which is essentially a binary tree + deduplicated values (same as idea 3.1).

There are several free ASN MMDBs [2,3] but you can also build your own MMDB files from any Prefix->Value mapping with the mmdbwriter library [4] or a CLI tool built on top of it like mmdbctl [5].

Assuming the ASN MMDB is fully loaded in memory, it would use around 60MB.

[1] https://maxmind.github.io/MaxMind-DB/

[2] https://dev.maxmind.com/geoip/docs/databases/asn/

[3] https://ipinfo.io/products/free-ip-data-downloads

[4] https://github.com/maxmind/mmdbwriter

[5] https://github.com/ipinfo/mmdbctl

(I work for IPinfo, but there are lots of other companies offering MMDB files).

[seligman99]

This is the same idea I used for my Cloud IP lookup tool [1], lets it all work in browser with a small file to search against

[1] https://cloud-ips.s3-us-west-2.amazonaws.com/index.html

[maxmouchet]

Oh this is nice, and a cool use of HTTP range requests!

[zdyxry]

cool

[gallypette]

https://github.com/adulau/mmdb-server

[mattpallissard]

"MaxMouchet DB"