1. A system comprising: a first back-end lookup computer storing a first plurality of domain name service (DNS) records, the back-end lookup computer being configured to receive multiplexed DNS queries; and a plurality of protocol computers in communication with the back-end lookup computer over a communication network, each of the plurality of protocol computers being configured to receive DNS queries, to identify valid DNS queries among the received DNS queries, to multiplex a plurality of valid DNS queries into a single query, and to send the single query to the lookup computer.