netsniff-ng For Linux

netsniff-ng is a high performance Linux network sniffer for packet inspection tool. Basically, it is similar to tcpdump, but it doesn't need one syscall per packet. Instead, it uses an memory mapped area within kernelspace for accessing packets without copying them to userspace (zero-copy mechanism).

This tool is useful for debugging your network, measuring performance throughput or creating network statistics of incoming packets on central network nodes like routers or firewalls.

By providing an unix domain socket client, you're able to export collected data during runtime (e.g. for Nagios).