This commit is contained in:
chris
2002-04-02 11:27:47 +00:00
parent f20c980274
commit 306d8fcefa

67
iftop.8
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@@ -16,7 +16,9 @@ iftop - display bandwidth usage on an interface by host
.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.
of hosts. \fBiftop\fP must be run with sufficient permissions to monitor all
network traffic on the \fIinterface\fP; see \fBpcap\fP(3) for more information,
but on most systems this means that it must be run as root.
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
@@ -24,15 +26,13 @@ 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.
By default, \fBiftop\fP shows all IP packets that pass through the filter, and
By default, \fBiftop\fP counts all IP packets that pass through the filter, and
the direction of the packet is determined according to the direction the packet
is moving across the interface. Using the \fB-n\fP option it is possible to
get \fBiftop\fP to show packets entering and leaving a given network. For
example, \fBiftop -n 10.0.0.0/255.0.0.0\fP will analyse packets flowing in and
out of the 10.* network.
\fBiftop\fP must be run as root.
Some other filter ideas:
.TP
\fBnot ether host ff:ff:ff:ff:ff:ff\fP
@@ -45,6 +45,33 @@ Count web traffic only, unless it is being directed through a local web cache.
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.
.TP
\fB-n\fP \fInet\fP/\fImask\fP
Specifies a network for traffic analysis. If specified, iftop will only
include packets flowing in to or out of the given network, and packet direction
is determined relative to the network boundary, rather than to the interface.
You may specify \fImask\fP as a dotted quad, such as /255.255.255.0, or as a
single number specifying the number of bits set in the netmask, such as /24.
.SH DISPLAY
When running, \fBiftop\fP uses the whole screen to display network usage. At
@@ -79,8 +106,8 @@ hosts responsible for the most traffic are displayed at the top of the list.
At the bottom of the display, various totals are shown, for instance:
.nf
total: 3.1K TX: 0.3M peaks: 64b totals: 64b 30b 10b
peak: 4.5K RX: 8M 4.5K 4.5K 0.1M 5K
total: 3.1K TX: 0.3M peaks: 64b totals: 64b 30b 10b
peak: 4.5K RX: 8M 4.5K 4.5K 0.1M 5K
.Sp
.fi
@@ -92,36 +119,10 @@ transmitted traffic, and the remaining colums show the 2, 10 and 40 second
averages. As with the per-host displays, the top line shows transmitted and the
bottom line received traffic.
.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.
.TP
\fB-n\fP \fInet\fP/\fImask\fP
Specifies a network for traffic analysis. If specified, iftop will only
include packets flowing in to or out of the given network, and packet direction
is determined relative to the network boundary, rather than to the interface.
You may specify \fImask\fP as a dotted quad, such as /255.255.255.0, or as a
single number specifying the number of bits set in the netmask, such as /24.
.SH SEE ALSO
.BR tcpdump (8),
.BR pcap (3),
.BR driftnet (1)
.BR driftnet (1).
.SH AUTHOR
Paul Warren <pdw@ex-parrot.com>