Manpage of stakstreams
Section: User Commands (1)
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stak - Statistical Traffic Analysis Kit
stakstreams [-i <interface>] [-p <prefix>] [-s <snarflen>] [-r <n> | -g | -k] [-q <n>] [-lcvjx] [-X <expression> [-0 <c>]] [-f <filtering expression>] [-um] [-t <n> | -y <n>[,<n>[,<n>]]] [-a <filename>] [-I <class/mask>[,<class/mask>...]] [-O <class/mask>[,<class/mask>...]] [filename]
is a part of the Statistical Traffic Analysis Kit (STAK), which is a set of
utilities designed to help an administrator to figure out what is happening in
his network at the moment.
determines flows, protocols or nodes causing the highest amount of traffic. This
utility is higly experimental.
accepts parameters in a standard, short
There are several options concerning the
common for the all
utilities - these options have been described in the
The remaining options, described in the
STREAMTRAFFIC ANALYZER SPECIFIC OPTIONS
are stakstreams-specific and do not apply to other
In this mode,
tries to keep track of every TCP connection and UDP or ICMP stream present on the interface. Every detected
conversation is allocated its own set of traffic counters; besides,
attempts to identify common protocols (like HTTP or FTP). The feature is still experimental, and consumes
HUGE amounts of system resources. Do not trust the -m and -f options, avoid leaving
somewhere in the background and without supervision.
The reports might be generated in three different ways:
- host-oriented reports
a list of most active (or least active, depending on sorting options) hosts is printed,
with an optional list of conversations below every entry.
- stream-oriented reports
print an overall list of most/least active streams.
- protocol-oriented reports
show the mostly utilized protocols, with an optional list of conversations classified
as a specific protocol below every entry.
- -0 c
Replace every NUL character (ASCII 0) with c before doing regular expression
based matching. Ignored if the
option was not specified. The default is '@'.
Color (ANSI-compatible) output in modes that support it (currently: stream
analyzer and "abusers detection" mode).
- -f f
BPF filter expression to use. Using this option causes
to ignore any packets not matching the specified BPF filter expression. For
a detailed description of BPF filter expressions syntax, consult the
Signal-based report generation policy. The reports are dumped
whenever stak receives a SIGUSR1 signal.
- -h -?
dumps a short help on available command-line options and quits, regardless
of other options.
- -i I
Bind to interface I. The default is 'eth0', which of course will cause a failure on
systems other than Linux. Make sure you specify the datalink prefix (see -p)
when you order stak to bind to an interface of an uncommon type.
Interactive report generation. The reports are dumped whenever
data is available on the standard input, which usually means you'll have
to press RETURN in order to generate a report.
Make stdout line-buffered. This option is useful when reports are redirected
(eg. using shell redirection) to a file.
Turns off asynchronous reverse DNS lookups.
will print numeric IPs rather than fully qualified domain names.
- -p N
Datalink layer header prefix length. Every (or at least almost every) known datalink
layer protocol prefixes a packet with its own header - which has to be stripped
before the actual data essential for stak (the IP protocol header) can be read.
is able to determine automatically how many bytes to skip only for the most common
datalink layer protocols (Ethernet, FDDI, TokenRing, loopback, PPP) - in other cases
the prefix length
must be specified using this option. It is EXTREMELY IMPORTANT to set the right value
might print completely irrevelant reports and output invalid IP addresses. The default
is autosense, or if that fails - 14 bytes, which is the length of an
- -q N
to quit after outputting N reports.
- -r N
Time-based report generation policy. The reports will be dumped on
stdout every N seconds. This is the default (with N = 0.1).
- -s N
Capture at least N bytes. For performance reasons,
does not acquire the whole packet from network, it just reads and processes first N
bytes. The default is 64 bytes, which might be not enough if you are using complicated BPF
expressions or filtering the packets using a regular expression. In such cases, it is
good to set the capture length to MTU on the interface. The value is automatically increased
to at least 1500 (which is the default MTU for an Ethernet interface) if one of -x, -E or -T
options is used. This option does NOT affect statistical data (amount of bytes, per-second byte rate)
collected by stak - the accounted packet size is always the 'real' one.
Print exact values. Normally,
uses SI prefixes (like k - kilo, M - mega, G - giga, T - tera) to make
the printed numeric values more attractive for a human being. The -v option
disables this feature, causing
to print exact values.
Clear the screen before printing each report. This assumes your terminal
is capable of understanding certain control sequences.
- -X r
Regular expression-based filtering. This option will cause
to ignore packets that DO NOT match specified regular expression. Before
any tests, NUL characters occuring in a packet are replaced with
an other character, as specified in the -0 option (the default is '@').
manual for a detailed description of POSIX regular expressions.
In addition to standard regex syntax, you may use the
\r (CR), \n (LF), \t (TAB), \\ (\)
and \xNN (hex NN) special sequences.
STREAM TRAFFIC ANALYZER SPECIFIC OPTIONS
- -z M
Limit memory used by the conversation engine to M kilobytes. When the amount of allocated memory gets
beyond the set limit, a number of least active conversation is dropped. DO NOT trust this option.
- -Z F
Drop F conversations after a memory overlimit. Default: 4000.
Output resource usage statistics (CPU, memory) before every report.
Use tabs instead of spaces to separate columns.
Increase verbosity level. This will print the guessed conversation protocol below every printed conversation
entry. Again, please keep on mind that the stream analyzer feature is highly experimental, and it still lacks
ability to recognize many common protocols. Only the basic ones (HTTP, FTP, FTP Data, POP3, SMTP) are supported
for now. The remaining streams are classified as "Unknown" and "Unidentified".
- -1 N
Node-driven reports. Print a list of N most/least active nodes (and, optionally, conversations associated with them)
- -2 N
Stream-driven reports. Print a list of N most/least active streams.
- -3 N
Protocol-driven reports. Output a list of N top protocols.
Brief output. Supress the conversation lists - valid only for node and protocol driven reports.
Consider received data counters. Makes sense only for node-driven reports. This is the default.
Consider sent data counters. As above, only for node-driven reports.
Consider momentary counters (default).
Consider overall counters.
Consider byte counters (default).
Consider packet counters.
Descending sort - the most active hosts/nodes/protocols first. This is the default.
Ascending sort - the least active hosts/nodes/protocols first.
BUGS AND LIMITATIONS
(stakstreams) operation mode is experimental. It consumes large amounts of system resources. Memory
leaks in code that provides this feature are possible; besides, the code still needs a lot of
improvements, as well as this manual page.
Mateusz Golicz <firstname.lastname@example.org>
Feel free to send comments, suggestions, bug reports, etc. The
author is not a native english speaker, and is aware of the fact that his english is far from
perfect. Because of that, reports on grammar or vocabulary mistakes in this manual are also welcome.
The asynchronous DNS resolver part was taken from
- a very handy traceroute replacement by Matt Kimball.
Copyright 2003 - 2004 Mateusz Golicz. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License, Version 2,
as published by the Free Software Foundation. A copy of this license is
distributed with this software in the file "COPYING".
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Read the
file "COPYING" for more details.
- GENERIC OPTIONS
- STREAM TRAFFIC ANALYZER SPECIFIC OPTIONS
- BUGS AND LIMITATIONS
- SEE ALSO
This document was created by
using the manual pages.
Time: 14:58:49 GMT, March 21, 2004