netsniff-ng is a free Linuxnetwork analyzer and networking toolkit originally written by Daniel Borkmann. Its gain of performance is reached by zero-copy mechanisms for network packets, so that the Linux kernel does not need to copy packets from kernel space to user space via system calls such as recvmsg. libpcap, starting with release 1.0.0, also supports the zero-copy mechanism on Linux for capturing, so programs using libpcap also use that mechanism on Linux.
Overview
netsniff-ng was initially created as a network sniffer with support of the Linux kernel packet-mmap interface for network packets, but later on, more tools have been added to make it a useful toolkit such as the iproute2 suite, for instance. Through the kernel's zero-copy interface, efficient packet processing can be reached even on commodity hardware. For instance, Gigabit Ethernet wire-speed has been reached with netsniff-ng's trafgen. The netsniff-ng toolkit does not depend on the libpcap library. Moreover, no special operating systempatches are needed to run the toolkit. netsniff-ng is free software and has been released under the terms of the GNU General Public License version 2. The toolkit currently consists of a network analyzer, packet capturer and replayer, a wire-rate traffic generator, an encrypted multiuser IP tunnel, a Berkeley Packet Filter compiler, networking statistic tools, an autonomous systemtrace route and more:
netsniff-ng, a zero-copy analyzer, packet capturer and replayer, itself supporting the pcapfile format
astraceroute, an autonomous system trace route utility with Geo-IP information
Distribution specific packages are available for all major operating system distributions such as Debian or Fedora Linux. It has also been added to Xplico's Network Forensic Toolkit, GRML Linux, SecurityOnion, and to the Network Security Toolkit. The netsniff-ng toolkit is also used in academia.
Basic commands working in netsniff-ng
In these examples, it is assumed that eth0 is the used network interface. Programs in the netsniff-ng suite accept long options, e.g., --in, --out, --dev.
For geographical AS TCP SYN probe trace route to a website:
astraceroute -d eth0 -N -S -H
For kernel networking statistics within promiscuous mode:
