Distributed Interactive Simulation (DIS) is being promoted as a tool to aid in design, prototyping and manufacturing of weapon systems, development of joint doctrine, mission planning, after-mission reviews and historical analysis. Future networked exercises promise hundreds of thousands of users interacting in a single "seamless battlefield". To achieve this goal, the evolving DIS standards have addressed the protocol for the data which must be exchanged between participants, and they embody a data reduction method known as "dead reckoning" to help reduce network bandwidth utilization. But this is only part of the solution. Connecting a simulator to a large exercise has been likened to "drinking from a firehose"; and most simulations, especially legacy simulators, simply cannot process the envisioned number of external entities. This paper discusses techniques for managing large quantities of entities, by filtering, organizing and prioritizing the DIS data for presentation to the simulation host.