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Developer(s) Paul Warren
Stable release 0.17
Written in C
Operating system Unix-like
Type Bandwidth usage / System monitor
License GNU General Public License
Website www.ex-parrot.com/pdw/iftop/

iftop is a command-line system monitor tool that produces a frequently-updated list of network connections. By default, the connections are ordered by bandwidth usage, with only the "top" bandwidth consumers shown.

The iftop website gives the following description: "iftop does for network usage what top(1) does for CPU usage. It listens to network traffic on a named interface and displays a table of current bandwidth usage by pairs of hosts. Handy for answering the question 'why is our ADSL link so slow?'".


Some options to iftop are listed below:

-n                  don't do hostname lookups
-N                  don't convert port numbers to services
-p                  run in promiscuous mode (show traffic between other
                    hosts on the same network segment)
-b                  don't display a bar graph of traffic
-B                  Display bandwidth in bytes
-i interface        listen on named interface
-f filter code      use filter code to select packets to count
                    (default: none, but only IP packets are counted)
-F net/mask         show traffic flows in/out of IPv4 network
-G net6/mask6       show traffic flows in/out of IPv6 network
-l                  display and count link-local IPv6 traffic (default: off)
-P                  show ports as well as hosts
-m limit            sets the upper limit for the bandwidth scale
-c config file      specifies an alternative configuration file

Some options while inside the iftop interface are listed below:

t                   toggles single line
f                   Open option to apply an extra filter

See also[edit]

External links[edit]