FIG. 4 is a flow chart of a method 400 for improving client subnet efficiency by equivalence class aggregation, according to some example embodiments. The method 400 may be performed by processing logic that may comprise hardware (e.g., decision-making logic, dedicated logic, programmable logic, and microcode), software (such as software run on a general-purpose computer system or a dedicated machine), or a combination of both. In one example embodiment, the processing logic refers to one or more components of the agent 120 or the recursive DNS server 110 described above with reference to FIG. 1. Notably, the steps recited below may be implemented in an order different than described and shown in the figure. Moreover, the method 400 may have additional steps not shown herein, but which can be evident for those skilled in the art from the present disclosure. The method 400 may also have fewer steps than outlined below and shown in FIG. 4.

The method for improving client subnet efficiency by equivalence class aggregation 400 may commence at operation 405 with a recursive DNS server 110 associated with a particular ISP 115 receiving a client query from a client 105. The client query includes a domain name, class and type which needs to be resolved.