netsniff-ng is a high performance Linux network sniffer for packet inspection. It is similar to analyzers like tcpdump, but without the need to perform system calls for fetching network packets. A memory-mapped area within kernelspace will be used for accessing packets, so there is no requirement for copying them to userspace (a 'zero-copy' mechanism). For this purpose, netsniff-ng is libpcap independent, but nevertheless supports the pcap file format for capturing, replaying, and performing offline analysis of pcap dumps. The project is focused on building a robust, clean, and secure analyzer and utilities that complete netsniff-ng as a support for penetration testing. netsniff-ng can be used for protocol analysis, reverse engineering, and network debugging.
Junkie is a real-time packet sniffer and analyzer. It is modular enough to accomplish many different tasks. It can be a helpful companion to the modern network administrator and analyst. Compared to previously available tools, junkie lies in between tcpdump and wireshark. Unlike tcpdump, its purpose is to parse protocols of any depth; unlike wireshark, though, it is designed to analyze traffic in real-time and so cannot parse traffic as exhaustively as wireshark does. In addition, its design encompasses extendability and speed. It has a plug-in system and high-level extension language that eases the development and combination of new functionalities; threaded packet capture and analysis for handling of high bandwidth networks; and a modular architecture to ease the addition of any protocol layer. It is based on libpcap for portability, and well-tested on professional settings.