That over-simplifies what the linked article says, plus there are things like blocked bloom filters and other tricks to speed things up.
Plus if he's allocating 128MB, well, just do it as a direct array 1 bit per IP4 address (which can be optimised to remove a few special blocks I guess) and skip any hashing.
Plus if he's allocating 128MB, well, just do it as a direct array 1 bit per IP4 address (which can be optimised to remove a few special blocks I guess) and skip any hashing.