The client query initiated by the client device 105 can be transmitted to a recursive DNS server 110 (also commonly referred to as a “DNS resolver”), which can be associated with a local ISP 115. The recursive DNS server 110 may include an agent 120 configured to implement at least some steps of the methods for improving client subnet efficiency by equivalence class aggregation described herein. The agent 120 may be a software module or an application installed on the recursive DNS server 110, such that it is an integrated part of recursive DNS server 110. Thus, the agent 120 can perform certain operations which attributed to the recursive DNS server 110. Alternatively, the agent 120 can be a stand-alone computing device operatively coupled to the recursive DNS server 110 and facilitating DNS resolution process. In yet other embodiments, some steps of the methods discussed herein can be performed by the agent 120 and some other steps of these methods can be performed by the recursive DNS server 110.