The Mutiny Fuzzing Framework is a network fuzzer that operates by replaying PCAPs through a mutational fuzzer. The goal is to begin network fuzzing as quickly as possible, at the expense of being thorough.
The general workflow for Mutiny is to take a sample of legitimate traffic, such as a browser request, and feed it into a prep script to generate a .fuzzer file. Then, Mutiny can be run with this .fuzzer file to generate traffic against a target host, mutating whichever packets the user would like. There are extensions that allow changing how Mutiny behaves, including changing messages based on input/output, changing how Mutiny responds to network errors, and monitoring the target in a separate thread.