-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.

-B     Display bandwidth rates in bytes/sec rather than bits/sec.

-i interface
       Listen to packets on interface.

-f filter code
       Use filter code to select the packets to count. Only IP packets are ever counted, so the specified
       code is evaluated as (filter code) and ip.

-F net/mask
       Specifies  an  IPv4  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 mask 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.

-G net6/mask6
       Specifies an IPv6 network for traffic analysis. The value of mask6 can be given as a prefix length
       or as a numerical address string for more compound bitmasking.

-c config file
       Specifies an alternate config file.  If not specified, iftop will use  ~/.iftoprc  if  it  exists.
       See below for a description of config files