NAME

NPF — NetBSD packet filter

DESCRIPTION

NPF is a layer 3 packet filter, supporting IPv4 and IPv6 as well as layer 4 protocols such as TCP, UDP, and ICMP. It was designed with a focus on high performance, scalability, and modularity.

NPF was written from scratch in 2009 and is distributed under the 2-clause BSD license.

FEATURES

NPF offers the traditional set of features provided by packet filters. Some key features are:

• Stateful inspection (connection tracking).
• Network address translation (NAT). This includes static (stateless) and dynamic (stateful) translation, port translation, bi-directional NAT, etc.
• IPv6-to-IPv6 network prefix translation (NPTv6).
• Tables for efficient IP sets.
• Application Level Gateways (e.g., to support traceroute).
• NPF uses BPF with just-in-time (JIT) compilation.
• Rule procedures and a framework for NPF extensions.
• Traffic normalization (extension).
• Packet logging (extension).

For a full set features and their description, see the NPF documentation and other manual pages.

SEE ALSO

libnpf(3), bpf(4), bpfjit(4), npf.conf(5), pcap-filter(7), npfctl(8)

NPF documentation

HISTORY

NPF first appeared in NetBSD 6.0.

AUTHORS

NPF was designed and implemented by Mindaugas Rasiukevicius.