NAME
trafshow - full screen show network traffic
SYNOPSIS
trafshow [-vpnb] [-a len] [-c conf] [-i name] [-s str] [-u port] [-R
refresh] [-P purge] [-F file | expr]
DESCRIPTION
TrafShow is a simple interactive program that gather the network
traffic from all libpcap-capable interfaces to accumulate it in memory
cache, and then separately display it on appropriated curses window in
line-narrowed manner as a list of network flows sorted by throughput.
Display updates occurs nearly in real time, asynchronously from the
data collecting. It look like a live show of traffic flows. Any kind of
network traffic are mixed together in the one live-show screen, an
Ethernet, IP, etc.
Hint: Please press ‘H’ key inside a show to get brief help!
The IP traffic can be aggregated by netmask prefix bits and service
ports to reorganize a heap of trivial flows into the treelike
hierarchies suitable for human perception. The user can glance over the
list of resulting flows and select at their to browse detail. So you
can deepen into the traffic inheritance hierarchy and inspect the
packets of each trivial flow in variety of presentations: raw-hex,
ascii, time-stamp.
The program make aggregation automatically when number of flows will
exceed some reasonable amount. Just a few seconds after launch may be
required for adaptation to your volume of traffic. Use -a len option
(see below) to overwrite the default behaviour.
TrafShow also listens on UDP port (9995 by default) for diverse feeders
of Cisco Netflow and then separately display the collected data in the
same manner as described above. The following versions of Netflow are
currently supported: V1, V5, V7. Use -u port option (see below) to
overwrite the default behaviour.
This program may be found wonderful at lest to locate suspicious
traffic on the net very quickly on demand, or to evaluate real time
traffic bandwidth utilization, in a simplest and convenient
environment. But it is not intended for collecting and analysis of the
network traffic for a long period of time, nor for billing!
The program pretend to be IPv6 compatible and ready to using, but it is
not tested enough. You can define INET6 to do so.
OPTIONS
-v Print detailed version information and exit.
-p Do not put interface(s) into promiscuous mode.
-n Do not convert numeric values to names (host addresses, port
numbers, etc.). The mode can be toggled On/Off during a show by
pressing the ‘N’ key.
-b To place a backflow entries near to the main streams in the
sorted list of traffic flows.
Note: this mode can raise the system load dangerously high
because it take a lot of CPU cycles!
-a len To aggregate traffic flows using IP netmask prefix len. This
option also turn on service ports aggregation. The len expected
as number of bits in the network portion of IP addresses (like
CIDR). The aggragation len can be changed during a show by
pressing the ‘A’ key, and turned Off by empty string.
Hint: Please use 0 to reduce output just for network services.
-c conf
Use alternate color config file instead of default
/etc/trafshow.
-i name
Listen on the specified network interface name. If unspecified,
TrafShow collect data from all network interfaces, configured UP
in the system. In the last case the system must supply enough
number of packet capture devices (like /dev/bpf#).
-s str To search and follow for list item matched by string, moving the
cursor bar. The found item try to stay highlighted. The mode can
be turned Off by ‘Ctrl-/’ key press or [re]entered again by ‘/’
key directly in the live show.
-u port
Listen on the specified UDP port number for the Cisco Netflow
feed. The default port number is 9995.
Hint: Please use 0 to disable this functionality.
-R refresh
Set the refresh period of data show to seconds, 2 seconds by
default. This option can be changed during a show by pressing
the ‘R’ key.
-P purge
Set the expired data purge period to seconds, 10 seconds by
default. This option can be changed during a show by pressing
the ‘P’ key.
-F file
Use file as input for the filter expression.
expr Select which packets will be displayed. If no expression is
given, all packets on the net will be displayed. Otherwise, only
packets for which expression is ‘true’ will be displayed.
The filter expression can be changed during a show by pressing
the ‘F’ key, and turned Off by empty string.
Please see tcpdump(1) man page for syntax of filter expression.
FILES
/etc/trafshow
The default colors configuration file if any.
$HOME/.trafshow
The personal file with the user defined colors.
COLORS
If TrafShow has been compiled with modern curses libraries such as
Slang or Ncurses it been able to show colored traffic on the color-
capable terminal. Hopefully, no special actions required to install
them because your system has it by default (leastwise last years).
The syntax of TrafShow color configuration file as follow:
default fcolor:bcolor
Set the default screen background color-pair
port[/proto] fcolor:bcolor
Set color pattern by service port
[proto] src[/mask][,port] dst[/mask][,port] fcolor:bcolor
Set color pattern by pair of source and destination addresses
The tokens *, any, or all matchs ANY in the pattern. Where fcolor is
foreground color and bcolor is background color.
The fcolor and bcolor may be one of the following:
black red green yellow blue magenta cyan white
It posible to indicate color as number from 0 to 7.
The upper-case Fcolor mean bright on. The upper-case Bcolor mean blink
on.
SEE ALSO
pcap(3), tcpdump(1), bpf(4)
ACKNOWLEDGEMENTS
Thanks to Van Jacobson <van(at)helios.ee.lbl.gov> and Steven McCanne
<mccanne(at)helios.ee.lbl.gov>, all of Lawrence Berkeley Laboratory,
University of California, Berkeley. Special thank to Jun-ichiro itojun
Hagino <itojun(at)iijlab.net> for IPv6 patches.
AUTHOR
Vladimir Vorobyev <bob(at)turbo.nsk.su>.
BUGS
Depending of traffic volume, TrafShow can take a lot of CPU cycles and
memory.
It is impossible to use packet matching expressions in the NetFlow
mode.
May 2004