Tribblix: manual page: nicstat.1

nicstat(1) User Commands nicstat(1)

NAME

nicstat - print network traffic statistics

SYNOPSIS

nicstat [-hvnsxpztualkMU] [-iinterface] [interval [count]]

DESCRIPTION

nicstat prints out network statistics for all network cards (NICs),
including packets, kilobytes per second, average packet sizes and
more.

OPTIONS

-h Display brief usage information (help).

-v Display nicstat version (and additional fields when
combined with '-l')

-n Show statistics for non-local (i.e. non-loopback)
interfaces only.

-s Display summary output - just the amount of data received
(read) and transmitted (written).

-x Display extended output. See OUTPUT section for details.

-U Display separate read and write utilization statistics.
This affects the default, extended (-x) and all (-a) format
outputs. For the default format the "Sat" statistic is
dropped to fit the output in 80 columns.

-M Display interface throughput statistics in Mbps (megabits
per second), instead of the default KB/s (kilobytes per
second).

NOTE - interface statistics are reported to operating
systems in bytes. nicstat does not know if Ethernet or
other hardware overheads are included in the statistic on
each platform.

-p Display output in parseable format. This outputs one line
per interface, in the following formats (which correspond
to the default, -x, -t and -u options; respectively):

time:In:rKB/s:wKB/s:rPk/s:wPk/s:%Util:Sat
time:In:rKB/s:wKB/s:rPk/s:wPk/s:%Util:Sat:IErr:OErr:Coll:NoCP:Defer
time:TCP:InKB:OutKB:InSeg:OutSeg:Reset:AttF:%ReTX:InConn:OutCon:Drops
time:UDP:InDG:OutDG:InErr:OutErr

where time is the number of seconds since midnight, Jan 1
1970 (UST) and the other fields are as described in the
OUTPUT section below.

NOTE - throughput statistics are always in KB/s (kilbytes
per second) for parseable formats, even if the "-M" flag
has been specified.

-z Skip interfaces for which there was zero traffic for the
sample period.

-t Show TCP statistics.

-u Show UDP statistics.

-a Equvalent to '-x -t -u'.

-l Just list interfaces.

-iinterface[,interface...]
Show statistics for only the interface(s) listed. Multiple
interfaces can be listed, separated by commas (,).

-k (Solaris only). Search for active network interfaces by
looking for kstat "link_state" statistics with a value of
1. This is only of value on systems running Solaris 10 (or
early releases of Solaris 11 Express), with Exclusive IP
Zones, where the interfaces given to an Exclusive IP Zone
are not otherwise visible. If you are running Solaris 9
(or earlier), or Solaris 11 (or later) you do not need this
option.

OPERANDS

interval Specifies the number of seconds between samples.

count Specifies the number of times that the statistics are
repeated. If no count is specified, nicstat will repeat
statistics indefinitely.

OUTPUT

The fields of nicstat's display are:

Time The time corresponding to the end of the sample shown, in
HH:MM:SS format (24-hour clock).

Int The interface name.

rKB/s, InKB
Kilobytes/second read (received).

wKB/s, OutKB
Kilobytes/second written (transmitted).

rMbps, RdMbps
Megabits/second read (received).

wMbps, WrMbps
Megabits/second written (transmitted).

rPk/s, InSeg, InDG
Packets (TCP Segments, UDP Datagrams)/second read
(received).

wPk/s, OutSeg, OutDG
Packets (TCP Segments, UDP Datagrams)/second written
(transmitted).

rAvs Average size of packets read (received).

wAvs Average size of packets written (transmitted).

%Util Percentage utilization of the interface. For full-duplex
interfaces, this is the greater of rKB/s or wKB/s as a
percentage of the interface speed. For half-duplex
interfaces, rKB/s and wKB/s are summed.

%rUtil, %wUtil
Percentage utilization for bytes read and written,
respectively.

Sat Saturation. This the number of errors/second seen for the
interface - an indicator the interface may be approaching
saturation. This statistic is combined from a number of
kernel statistics. It is recommended to use the '-x'
option to see more individual statistics (those mentioned
below) when attempting to diagnose a network issue.

IErr Packets received that could not be processed because they
contained errors

OErr Packets that were not successfully transmitted because of
errors

Coll Ethernet collisions during transmit.

NoCP No-can-puts. This is when an incoming packet can not be
put to the process reading the socket. This suggests the
local process is unable to process incoming packets in a
timely manner.

Defer Defer Transmits. Packets without collisions where first
transmit attempt was delayed because the medium was busy.

Reset tcpEstabResets. The number of times TCP connections have
made a direct transition to the CLOSED state from either
the ESTABLISHED state or the CLOSE-WAIT state.

AttF tcpAttemptFails - The number of times that TCP connections
have made a direct transition to the CLOSED state from
either the SYN-SENT state or the SYN-RCVD state, plus the
number of times TCP connections have made a direct
transition to the LISTEN state from the SYN-RCVD state.

%ReTX Percentage of TCP segments retransmitted - that is, the
number of TCP segments transmitted containing one or more
previously transmitted octets.

InConn tcpPassiveOpens - The number of times that TCP connections
have made a direct transition to the SYN-RCVD state from
the LISTEN state.

OutCon tcpActiveOpens - The number of times that TCP connections
have made a direct transition to the SYN-SENT state from
the CLOSED state.

Drops tcpHalfOpenDrop + tcpListenDrop + tcpListenDropQ0.

tcpListenDrop and tcpListenDropQ0 - Number of connections dropped
from the completed connection queue and incomplete connection queue,
respectively. tcpHalfOpenDrops - Number of connections dropped after
the initial SYN packet was received.

The first set of statistics printed are averages since system boot.
If no interval operand is specified, or a count value of "1" is
specified, this will be the only sample printed.

EXAMPLES

Print average statistics from boot time to now only:

$ nicstat

Print statistics for all interfaces, every 3 seconds:

$ nicstat 3

Print statistics for all interfaces, every 5 seconds, finishing after
10 samples:

$ nicstat 5 10

Print statistics every 3 seconds, only for interfaces "hme0" and
"hme1":

$ nicstat -i hme0,hme1 3

NOTES

The way that saturation is reported is a best effort, as there is no
standardized naming to capture all errors related to an interface's
inability to receive or transmit a packet. Monitoring %Util and
packet rates, along with an understanding of the specific NICs may be
more useful in judging whether you are nearing saturation.

4th Berkeley Distribution 27 Jan 2014 nicstat(1)