Copyright (c) 2019 Mindaugas Rasiukevicius <rmind at netbsd org>
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.Dd August 3, 2019 .Dt NPF-PARAMS 7 .Os .Sh NAME .Nm npf-params .Nd tunable NPF parameters .Sh DESCRIPTION NPF supports a set of dynamically tunable parameters.
p
All parameter values are integers and should generally be between and INT_MAX,
unless specified otherwise.
Some parameters values can be negative; such values would typically
have a special meaning.
Enable/disable switches should be represented as boolean values 0 ("off")
or 1 ("on").
.Sh PARAMETERS
l -tag -width "123456" ---
l -tag -width "123456" t Li bpf.jit BPF just-in-time compilation: enables or disables
.Xr bpfjit 4
support.
Some machine architectures are not presently supported by
.Xr bpfjit 4 .
Setting this parameter to off stops NPF from trying to enable this
functionality, and generating a warning if it is unable to do so.
Default: 1.
.El
---
l -tag -width "123456" t Li gc.step Number of connection state items to process in one garbage collection
(G/C) cycle.
Must be positive number.
Default: 256.
.El
---
t Li state.generic Generic state tracking parameters for non-TCP flows.
All timeouts are in seconds and must be zero or positive.
l -tag -width "123456" t Li timeout.new Timeout for new ("unsynchronized") state.
Default: 30.
t Li timeout.established Timeout for established ("synchronized") state.
Default: 60.
t Li timeout.closed Timeout for closed state.
Default: 0.
.El
---
t Li state.tcp State tracking parameters for TCP connections.
All timeout values are in seconds.
l -tag -width "123456" t Li max_ack_win Maximum allowed ACK window.
Default: 66000.
t Li strict_order_rst Enforce strict order RST.
Default: 1.
-
t Li timeout.new Timeout for a new connection in "unsynchronized" state.
Default: 30.
t Li timeout.established Timeout for an established connection ("synchronized" state).
Default: 86400.
t Li timeout.half_close Timeout for the half-close TCP states.
Default: 3600.
t Li timeout.close Timeout for the full close TCP states.
Default: 10.
t Li timeout.time_wait Timeout for the TCP time-wait state.
Default: 240.
.El
---
t Li portmap.min_port Lower bound of the port range used when selecting the port for dynamic NAT
with port translation enabled.
Default: 1024 (also the lowest allowed value).
t Li portmap.max_port Upper bound of the port range as described above.
Default: 65535 (also the highest allowed value).
---
.El
-----
.Sh EXAMPLES
An example line in the
.Xr npf.conf 5
configuration file:
d -literal -offset indent set state.tcp.strict_order_rst on # "on" can be used instead of 1
set state.tcp.timeout.time_wait 0 # destroy the state immediately
.Ed
-----
.Sh SEE ALSO
.Xr libnpf 3 ,
.Xr npfkern 3 ,
.Xr bpfjit 4 ,
.Xr npf.conf 5 ,
.Xr pcap-filter 7 ,
.Xr npfctl 8
-----
.Sh AUTHORS
NPF
was designed and implemented by
.An Mindaugas Rasiukevicius .
Indexes created Mon Oct 27 04:09:48 GMT 2025