Going from an IPv4 address to an ASN in Python 2 with Unix brute force

The author describes a brute-force approach to map IPv4 addresses to Autonomous System Numbers in Python 2 using a sparse file. By storing ASN data for each /24 network block in a file, the method allows efficient lookups with minimal memory usage. The implementation proved straightforward and created a 53 MB data file covering about 16.5 million /24 networks.