– display bandwidth usage on an interface by host. iftop listens to network traffic on a named interface, or on the first interface it can find which looks like an external interface if none is
specified, and displays a table of current bandwidth usage by pairs of hosts. iftop must be run with sufficient permissions to monitor all net-
work traffic on the interface for more information, but on most systems this means that it must be run as root.
[root@my-home my-home]# iftop interface: p5p1 IP address is: 192.168.25.198 MAC address is: fffffff0:4d:ffffffa2:4e:ffffffa2:fffffffc [root@my-home my-home]#
- h Print a summary of usage.
- n Don’t do hostname lookups.
- N Do not resolve port number to service names
- p Run in promiscuous mode, so that traffic which does not pass directly through the specified interface is also counted.
- P Turn on port display.
- l Display and count datagrams addressed to or from link-local IPv6 addresses. The default is not to display that address category.
- b Don’t display bar graphs of traffic.
- m limit
- Set the upper limit for the bandwidth scale. Specified as a number with a ’K’, ’M’ or ’G’ suffix.
- B Display bandwidth rates in bytes/sec rather than bits/sec.
- i interface, Listen to packets on interface.