Computer network researchers, system engineers and network operators have an increasing need for network traces. These are necessary to build and evaluate communication systems. This ranges from developing intrusion detection systems over evaluating network protocols or system design decisions, up to education in network security. Unfortunately, availability of real-world traces is very scarce, mainly due to privacy and security concerns. Making recorded data anonymous helps to mitigate this problem. Available anonymization systems, however, do not provide sufficient flexibility, extensibility or ease of use. Therefore, we developed a generic framework for traffic anonymization that can easily be configured by anonymization profiles. Such profiles ensure an easy adaptation of the information actually being made anonymous to different environments or local legislation. Furthermore, our framework supports flexible application of arbitrary anonymization primitives to every protocol field. Due to its extensibility our framework provides an easy incorporation of new anonymity-enhancing techniques, too. Additionally, it prevents accidental disclosure of private data by applying a technique called defensive transformation. Finally, it can be used for online as well as offline anonymization of network traffic.