Freedom251 › Network Protocol Analyzers
netsniff-ng
What netsniff-ng is
netsniff-ng is a free Linux networking toolkit for packet analysis, network development, debugging, auditing, and reconnaissance. Its packet analyzer captures traffic and replays PCAP files, while the included trafgen utility generates packets using a multithreaded, low-level design. Zero-copy mechanisms avoid copying packets between kernel space and user space during reception and transmission.
The toolkit also bundles mausezahn, ifpps, curvetun, astraceroute, flowtop, and bpfc. These utilities cover packet generation, network statistics, tunneling, tracing, connection tracking, and BPF compilation. The project labels mausezahn and curvetun experimental and cautions against using them in production environments.
netsniff-ng is open source under the GNU General Public License version 2.0 and is free to use. Installation instructions cover Linux kernels with CONFIG_PACKET_MMAP enabled and explain how to build from source with configure and make. Depending on the utilities selected, a build may need libraries such as libnl3, libpcap, libncurses, or libnetfilter-conntrack. The project documents Git and GPG signature verification for releases and points users to a public mailing list and online FAQ. It describes the toolkit as working, while noting it may not be feature complete and carries no bug-free guarantee.
Who it suits
netsniff-ng suits Linux users who need command-line tools for packet capture and replay, traffic generation, or network analysis. It may also fit network developers and administrators working on debugging, auditing, tracing, or reconnaissance tasks.
What it does well
- Captures traffic and replays PCAP files.
- Includes a multithreaded packet generator.
- Zero-copy mechanisms cover reception and transmission.
- Bundles tools for statistics, tracing, tunneling, and BPF compilation.
- Open source under GNU GPL version 2.0.
What to know first
- Linux is the only listed platform.
- Building from source requires a supported kernel configuration.
- Some utilities may require additional libraries.
- Mausezahn and curvetun are marked experimental.
Limits
There is no paid-plan limit because netsniff-ng is free. The project says it may not be feature complete, offers no guarantee that the tools are bug-free, and advises against production use of mausezahn and curvetun.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| netsniff-ng | Free, open source toolkit for Linux networking | Free |
As github.com lists them, read 9 Oct 2026. The maker's own page has the final word.
Getting started
- Open the project website on GitHub.
- Use a Linux system with CONFIG_PACKET_MMAP enabled.
- Build from source with configure and make.
- Install any libraries required by the utilities you choose.
- Consult the online FAQ or public mailing list for questions.
Verdict
Choose netsniff-ng if you need a free Linux toolkit combining packet capture, replay, generation, and related network utilities. Look elsewhere if you need a platform beyond Linux or production use of mausezahn or curvetun.
Questions
How much does netsniff-ng cost?
The toolkit is free, with a listed price of $0.
Is netsniff-ng open source?
Yes. It is licensed under the GNU General Public License version 2.0.
Which platform does it support?
Linux is the listed platform. The installation instructions cover Linux kernels with CONFIG_PACKET_MMAP enabled.
Can it handle PCAP files?
Yes. Its packet analyzer can capture traffic and replay PCAP files.
How is it installed?
The project describes building from source with configure and make. Depending on the utilities selected, libraries including libnl3, libpcap, libncurses, and libnetfilter-conntrack may be required.
Facts from netsniff-ng's own pages
- Build and platform
- The installation instructions support Linux kernels with CONFIG_PACKET_MMAP enabled and describe building from source with configure and make. · github.com, 9 Oct 2026
- Dependencies
- Building the utilities can require libraries including libnl3, libpcap, libncurses, and libnetfilter-conntrack, depending on the tools built. · github.com, 9 Oct 2026
- Experimental tools
- The project marks mausezahn and curvetun as experimental and says they should not be used in production environments. · github.com, 9 Oct 2026
- Included utilities
- The toolkit also includes mausezahn, ifpps, curvetun, astraceroute, flowtop, and bpfc for packet generation, network statistics, tunneling, tracing, connection tracking, and BPF compilation. · github.com, 9 Oct 2026
- License
- The toolkit is open source under the GNU General Public License version 2.0. · github.com, 9 Oct 2026
- Limitations
- The project describes its status as working, says it may not be feature complete, and provides no guarantee that the tools are free of bugs. · github.com, 9 Oct 2026
- Packet analysis
- netsniff-ng provides a zero-copy packet analyzer that can capture and replay pcap files. · github.com, 9 Oct 2026
- Packet generation
- trafgen is a multithreaded low-level zero-copy network packet generator. · github.com, 9 Oct 2026
- Performance
- Built-in zero-copy mechanisms avoid copying packets between kernel space and user space during reception and transmission. · github.com, 9 Oct 2026
- Purpose
- netsniff-ng is a free Linux network analyzer and networking toolkit for network development, debugging, analysis, auditing, and reconnaissance. · github.com, 9 Oct 2026
- Release verification
- The project documents verifying releases with Git and GPG signatures. · github.com, 9 Oct 2026
- Support
- The project directs users to its public mailing list and online FAQ for questions and feedback. · github.com, 9 Oct 2026
Where netsniff-ng stands on Freedom251
- Network Protocol Analyzers#15 of 30