NPF(7) | Miscellaneous Information Manual | NPF(7)

# 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.

# 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).
- Use of BPF with just-in-time (JIT) compilation.
- Rule procedures and a framework for `NPF` extensions.
- Traffic normalisation (extension).
- Packet logging (extension).

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

# SEE ALSO

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

NPF project page

NPF documentation website

# HISTORY

`NPF` was written from scratch in 2009 and is distributed under the 2-clause BSD license. It first appeared in NetBSD 6.0.

# AUTHORS

`NPF` was designed and implemented by Mindaugas Rasiukevicius.

August 11, 2019 | NetBSD 11.0