PKTSTAT(1) BSD General Commands Manual PKTSTAT(1)NAMEpktstat — display packet activity on a crt
SYNOPSISpktstat [-1BcFlnpPtT] [-a abbrev] [-A file] [-i interface] [-k keeptime]
[-m maxbps] [-w waittime] [filter-expr]
DESCRIPTION
The pktstat program displays a real-time summary of packet activity on an
interface. Each line displays the data rate associated with different
classes of packets.
pktstat understands the following command line options:
-1 Single-shot (batch) mode. pktstat collects data for waittime
seconds (see -w option) then emits a line indicating the num‐
ber of flows detected, and the period of data capture in sec‐
onds. Then, each flow line is printed in the form of the
number of data link octets associated with the flow, the num‐
ber of data link frames (packets), and then the flow descrip‐
tion.
-a abbrev
Add abbrev to the list of abbreviation patterns. (See below
for details.)
-A file
Read abbreviation patterns from the given file. (See
Abbreviations, below.) If the option -A none is given, then
default abbreviation files are not loaded.
-B Display data rates in bytes per second (Bps) instead of in
bits per second (bps).
-c Do not combine some packet classes into one class. For exam‐
ple, TCP connections are kept as two separate flows.
-F Show full hostnames. Normally, hostnames are truncated to
the first component of their domain name before display.
-i interface
Listen on the given interface. If not specified, a suitable
interface is chosen.
-k keeptime
When no packets have been seen for a particular class, retain
an entry on the display for this many screen seconds.
Defaults to 10.
-l Display and sort flows by when they were last seen. (Incom‐
patible with -t)
-m maxbps
Fix the maximum bit rate for the interface at maxbps instead
of auto-detecting it.
-n Do not try and resolve hostnames or service port numbers.
-p Show packet counts instead of bit counts.
-P Do not try to put the interface into promiscuous mode.
-t "Top" mode. Sorts the display by bit count (or packet count
if -p was given) instead of by the name.
-T Show totals.
-w waittime
Refresh the display every waittime seconds. The default is 5
seconds.
filter-expr
Only consider packets matching the given filter-expr. If no
filter is provided, all packets are considered. See
tcpdump(8) for information on valid expressions.
If the terminal supports it, the display briefly highlights in bold new
connections or old connections carrying data after a period of inactiv‐
ity.
Simple statistics about the interface are also displayed such as the cur‐
rent and average bit rates (measured just above the data link layer).
Load averages refer to bit rate decayed averages for the last 1, 5 and 15
minutes.
During display, the following keystrokes are recognised:
q quit
Ctrl-L redraw screen
t toggle the -t flag (top mode)
T toggle the -T flag (totals mode)
w allows changing of the -w flag value (wait time)
n toggle the -n flag (numeric display)
p toggle the -p flag (packets instead of bits)
b | B toggle the -B flag (bps or Bps)
f | F toggle the -F flag (full hostnames)
r reset collected statistics (min, max, etc.), flush flow
history and reset DNS/service and fragment caches
l show and sort flows by when they were last active
? toggle display of help/status text at the bottom of the
display
Packet classes
All packet classes, or flows, are "tagged" with a descriptive string,
such as ‘tcp ftpserver:20524 <-> cathexis:17771’.
In addition to being tagged, some protocol-state information can be asso‐
ciated with a flow. This is displayed immediately below a flow line.
Descriptive information for FTP, HTTP, X11 and SUP connections is deter‐
mined from simple decoding of some packets. If the connection is 'open',
it is introduced with a right angle shape (+), otherwise it is introduced
with a hyphen character.
tcp www:80 <-> hamartia:19179
+ GET /index.html
Abbreviations
Abbreviation patterns are a way of further combining flows. As packets
are decoded, their flow name is constructed at the various protocol lay‐
ers. At address combining stage (where arrows such as ‘->’ are inserted)
and at the final display stage, flow names are checked against a list of
abbreviation patterns, and the abbreviation's name substituted if a match
is found. For example, the pattern ‘* <-> *:domain’ will match DNS pack‐
ets in both the UDP and TCP layers.
Abbreviations take the form [abbrev@]pattern. The pattern part can con‐
tain the wildcard character, asterisk ‘*’ which matches zero or more non-
space characters. The space character matches one or more whitespace
characters. Leading and trailing spaces are ignored.
If the optional abbrev is not specified, the the pattern text itself is
used as the abbreviation.
Patterns are checked in the order given on the command line or in the
files, i.e. as soon as one of the patterns matches a tag, no further pat‐
terns are considered. Recall that patterns can be applied multiple times
to a tag.
A patterns file can contain blank lines, which are ignored. Comment
lines that commence with a ‘#’ character are also ignored.
After processing all command line abbreviations and abbreviation files,
pktstat looks for and loads the files .pktstatrc, $HOME/.pktstatrc and
/usr/local/etc/pktstatrc. This behaviour is suppressed by supplying an
-A none option.
EXAMPLES
Here are the contents of my .pktstatrc file:
dns @ udp *:domain <-> *
dns @ udp * <-> *:domain
irc @ udp 192.168.0.81:6666 <-> *
SEE ALSObpf(4), tcpdump(8)AUTHORS
David Leonard, leonard@users.sourceforge.net
BUGS
DNS lookups can take too much time, possibly leading to missed packets.
The data rates do not take into account data link framing overhead or
compression savings at the data link layer.
The direction of traffic is not taken into account: both ingress and
egress data rates are combined. If you want to separate them, you will
need to use a filter expression.
Descriptive information for X11, FTP, HTTP and SUP flows is derived from
the very first packets sent on those protocols. If you start pktstat
after any of these flows have commenced, there may be no description
available for them.
BSD June 23, 2002 BSD
