Files
iftop/iftop.8
chris 595790691f ""
2002-03-27 18:56:50 +00:00

96 lines
2.9 KiB
Groff

.TH IFTOP 8
.\"
.\" iftop.8:
.\" Manual page for iftop.
.\"
.\" $Id$
.\"
.SH NAME
iftop - display bandwidth usage on an interface by host
.SH SYNOPSIS
\fBiftop\fP \fB-h\fP |
[\fB-d\fP] [\fB-p\fP] [\fB-i\fP \fIinterface\fP] [\fB-f\fP \fIfilter code\fP]
.SH DESCRIPTION
\fBiftop\fP listens to network traffic on a named \fIinterface\fP, or \fBeth0\fP
if none is specified, and displays a table of current bandwidth usage by pairs
of hosts.
When run, \fBiftop\fP displays, for each pair of hosts, the rate at which data
is sent and received averaged over 1, 5 and 20 second intervals. The direction
of data flow is indicated by arrows, <= and =>. In addition, a simple bar graph
shows the 5-second average. The pairs of hosts which consume the most bandwidth
are displayed at the top of the screen, and totals for all hosts are shown at
the bottom of the screen.
By default, \fBiftop\fP will look up the hostnames associated with addresses it
finds in packets. This can cause substantial traffic of itself, and may result
in a confusing display. You may wish to suppress display of DNS traffic by
using filter code such as \fBnot port domain\fP, or switch it off entirely,
by using the \fB-d\fP option or by pressing \fBR\fP when the program is running.
Some other filter ideas:
.TP
\fBnot ether host ff:ff:ff:ff:ff:ff\fP
Ignore ethernet broadcast packets.
.TP
\fBport http and not host \fP\fIwebcache.example.com\fP
Count web traffic only, unless it is being directed through a local web cache.
.TP
\fBicmp\fP
How much bandwith are users wasting trying to figure out why the network is
slow?
.SH OPTIONS
.TP
\fB-h\fP
Print a summary of usage.
.TP
\fB-d\fP
Don't do hostname lookups. This setting may be altered at run time.
.TP
\fB-p\fP
Run in promiscuous mode, so that traffic which does not pass directly through
the specified interface is also counted.
.TP
\fB-i\fP \fIinterface\fP
Listen to packets on \fIinterface\fP.
.TP
\fB-f\fP \fIfilter code\fP
Use \fIfilter code\fP to select the packets to count. Only IP packets are ever
counted, so the specified code is evaluated as \fB(\fP\fIfilter code\fP\fB) and ip\fP.
.SH SEE ALSO
.BR tcpdump (8),
.BR pcap (3),
.BR driftnet (1)
.SH AUTHOR
Paul Warren <pdw@ex-parrot.com>
.SH VERSION
$Id$
.SH COPYING
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.