fprobe-ulog − a NetFlow probe
fprobe-ulog [options] remote:port[/[local][/type]] ...
fprobe-ulog − libipulog-based tool that collect network traffic data and emit it as NetFlow flows towards the specified collector.
-h |
Display short help |
-U <mask>
ULOG group bitwise mask. [default=1]
-s <seconds>
How often scan for expired flows. [default=5]
-g <seconds>
Fragmented flow lifetime. [default=30]
-d <seconds>
Idle flow lifetime (inactive timer). [default=60]
-e <seconds>
Active flow lifetime (active timer). [default=300]
-n <version>
NetFlow version for use (1, 5, 7). [default=5]
-a <address>
Use address as source for NetFlow flow.
-X <rule[,...]>
Comma separated list of
interface name to SNMP-index conversion rules. Each
rule consists of interface base name and
SNMP-index base separated by colon (e.g. ppp:200).
Final SNMP-index is sum of corresponding SNMP-index
base and interface number.
In the above example SNMP-index of interface ppp11 is
211.
If interface name did not fit to any of conversion rules then SNMP-index will be taken from kernel.
-M |
Use the netfilter mark as Type Of Service value. |
-b <flows>
Memory bulk size. [default=200
or 10000]
Note that maximum and default values depends on compiling
options (--with-membulk parameter).
-m <kilobytes>
Memory limit for flows cache (0=no limit). [default=0]
-q <flows>
Pending queue length.
[default=100]
Each captured packet at first puts into special buffer
called ‘pending queue’. Purpose of this buffer
is to separate most time-critical packet capture thread from
other.
-B <kilobytes>
Kernel capture buffer size
(0=don’t change). [default=0]
Increase kernel capture buffer size is most adequate way to
prevent packets loss.
Note that maximum allowed size of the buffer in Linux
limited and generally relatively small, so it should need to
change the maximum: sysctl -w net/core/rmem_max=4194304
-r <priority>
Real-time priority
(0=disabled). [default=0]
If parameter greater then zero fprobe-ulog will use
real-time scheduling policy to prevent packets loss. Note
that possible values for this option depends on operating
system.
-t <B:N>
Emitting rate limit (0:0=no
limit). [default=0:0]
Produce N nanosecond delay after each B bytes
sent. This option may be useful with slow interfaces and
slow collectors. Note that the suspension time may be longer
than requested because the argument value is rounded up to
an integer multiple of the sleep resolution (it depends on
operating system and hardware) or because of the scheduling
of other activity by the system.
See BUGS section.
-c <directory>
Directory to chroot to.
-u <user>
User to run as.
-v <level>
Maximum displayed log level. (0=EMERG, 1=ALERT, 2=CRIT, 3=ERR, 4=WARNING, 5=NOTICE, 6=INFO, 7=DEBUG) [default=6]
-l <[dst][:id]>
Log destination (0=none,
1=syslog, 2=stdout, 3=both) and log/pidfile identifier.
[default=1]
This option allows to select opportune log destination and
process identifier. The identifier helps to distinguish
pidfile and logs of one fprobe-ulog process from
other.
Note that if log destination contains
‘stdout’ (equal 2 or 3)
fprobe-ulog will run in foreground.
remote:port/local/type
Parameters remote and
port are respectively define address and port of the
NetFlow collector.
The local parameter allows binding certain local IP
address with specified collector. If the parameter is
omitted the value (if any) of -a option will be used.
The type parameter determines emitting behavior. It
may be ‘m’ for mirroring (by default) and
‘r’ for collectors round-robin rotating.
You may specify multiple collectors.
fprobe-ulog -Xeth:100,ppp:200 localhost:2055
Reasonable
configuration to run under heavy load:
fprobe-ulog -B4096 -r2 -q10000 -t10000:10000000
localhost:2055
Send packets to
collector at 10.1.1.1:2055 and distribute them between
collectors at 10.1.1.2:2055 and at 10.1.1.3:2055 on a
round-robin basis:
fprobe-ulog 10.1.1.1:2055 10.1.1.2:2055//r
10.1.1.3:2055//r
Slow
interfaces and slow collectors.
There are may be problems with slow interfaces and slow
collectors. It effects as emitted packets loss. On the one
hand silent non-blocking sendto() implementation can’t
guarantee that packet was really sent to collector - it may
be dropped by kernel due to outgoing buffer shortage (slow
interface’s problem) and on the other hand packet may
be dropped on collector’s machine due the similar
reason - incoming buffer shortage (slow collector’s
problem).
Use -t option as workaround for this issue.
Locally
originated packets and their timestamps.
Locally originated packets does not contains valid
timestamps. Therefore fprobe-ulog fill timestamp by
itself on act of receive such packet. Unfortunately, between
capturing packet by netfilter code and receiving it by
fprobe-ulog may occur certain lags, thus timestamps
of locally originated packets generally inexact.
It is possible to fix this problem entirely by trivial
kernel patch (see contrib/ipt_ULOG.patch).
iptables(8)
http://freshmeat.net/projects/ulogd
http://www.cisco.com/go/netflow