diff options
| author | Jacob McDonnell <jacob@jacobmcdonnell.com> | 2026-04-25 14:02:27 -0400 |
|---|---|---|
| committer | Jacob McDonnell <jacob@jacobmcdonnell.com> | 2026-04-25 14:02:27 -0400 |
| commit | 6d8bdc65446a704d0750217efd05532fc641ea7d (patch) | |
| tree | 8ae6d698b3c9801750a8b117b3842fb369872a3a /static/openbsd/man4/pflow.4 | |
| parent | 2f467bd7ff8f8db0dafa40426166491d7f57f368 (diff) | |
docs: OpenBSD Man Pages Added
Diffstat (limited to 'static/openbsd/man4/pflow.4')
| -rw-r--r-- | static/openbsd/man4/pflow.4 | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/static/openbsd/man4/pflow.4 b/static/openbsd/man4/pflow.4 new file mode 100644 index 00000000..bdcf5e95 --- /dev/null +++ b/static/openbsd/man4/pflow.4 @@ -0,0 +1,136 @@ +.\" $OpenBSD: pflow.4,v 1.19 2014/03/29 11:26:03 florian Exp $ +.\" +.\" Copyright (c) 2008 Henning Brauer <henning@openbsd.org> +.\" Copyright (c) 2008 Joerg Goltermann <jg@osn.de> +.\" +.\" Permission to use, copy, modify, and distribute this software for any +.\" purpose with or without fee is hereby granted, provided that the above +.\" copyright notice and this permission notice appear in all copies. +.\" +.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +.\" +.Dd $Mdocdate: March 29 2014 $ +.Dt PFLOW 4 +.Os +.Sh NAME +.Nm pflow +.Nd kernel interface for pflow data export +.Sh SYNOPSIS +.Cd "pseudo-device pflow" +.Sh DESCRIPTION +The +.Nm +interface is a pseudo-device which exports +.Nm +accounting data from the kernel using +.Xr udp 4 +packets. +.Nm +is compatible with netflow version 5 and IPFIX (10). +The data is extracted from the +.Xr pf 4 +state table. +.Pp +Multiple +.Nm +interfaces can be created at runtime using the +.Ic ifconfig pflow Ns Ar N Ic create +command. +Each interface must be configured with a flow receiver IP address +and a flow receiver port number. +.Pp +Only states created by a rule marked with the +.Ar pflow +keyword are exported by the +.Nm +interface. +.Pp +The +.Nm +interface will attempt to export multiple +.Nm +records in one +UDP packet, but will not hold a record for longer than 30 seconds. +The packet size and thus the maximum number of flows is controlled by the +.Cm mtu +parameter of +.Xr ifconfig 8 . +.Pp +Each packet seen on this interface has one header and a variable number of +flows. +The header indicates the version of the protocol, number of +flows in the packet, a unique sequence number, system time, and an engine +ID and type. +Header and flow structs are defined in +.In net/if_pflow.h . +.Pp +There is a one-to-one correspondence between packets seen by +.Xr bpf 4 +on the +.Nm +interface and packets sent out to the flow receiver. +That is, a packet with 30 flows on +.Nm +means that the same 30 flows were sent out to the receiver. +.Pp +The +.Nm +source and destination addresses are controlled by +.Xr ifconfig 8 . +.Cm flowsrc +is the sender IP address of the UDP packet which can be used +to identify the source of the data on the +.Nm +collector. +.Cm flowdst +defines the collector IP address and the port. +The +.Cm flowdst +IP address and port must be defined to enable the export of flows. +.Pp +For example, the following command sets 10.0.0.1 as the source +and 10.0.0.2:1234 as destination: +.Bd -literal -offset indent +# ifconfig pflow0 flowsrc 10.0.0.1 flowdst 10.0.0.2:1234 +.Ed +.Pp +The protocol is set to IPFIX with the following command: +.Bd -literal -offset indent +# ifconfig pflow0 pflowproto 10 +.Ed +.Sh SEE ALSO +.Xr netintro 4 , +.Xr pf 4 , +.Xr udp 4 , +.Xr pf.conf 5 , +.Xr ifconfig 8 , +.Xr tcpdump 8 +.Sh STANDARDS +.Rs +.%A B. Claise +.%D January 2008 +.%R RFC 5101 +.%T "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information" +.Re +.Sh HISTORY +The +.Nm +device first appeared in +.Ox 4.5 . +.Sh BUGS +A state created by +.Xr pfsync 4 +can have a creation or expiration time before the machine came up. +In this case, +.Nm +pretends such flows were created or expired when the machine came up. +.Pp +The IPFIX implementation is incomplete: +The required transport protocol SCTP is not supported. +Transport over TCP and DTLS protected flow export is also not supported. |
