drool can replay DNS traffic from packet capture (PCAP) files and send it to a specified server, with options such as to manipulate the timing between packets, as well as loop packets infinitely or for a set number of iterations. This tool's goal is to be able to produce a high amount of UDP packets per second and TCP sessions per second on common hardware.

The purpose can be to simulate Distributed Denial of Service (DDoS) attacks on the DNS and measure normal DNS querying. For example, the tool could enable you to take a snapshot of a DDoS and be able to replay it later to test if new code or hardening techniques are useful, safe & effective. Another example is to be able to replay a packet stream for a bug that is sequence- and/or timing-related in order to validate the efficacy of subsequent bug fixes.