ping -f

man ping
/-f
n

       -f     Flood ping. For every ECHO_REQUEST sent a period ‘‘.’’ is  printed,  while  for  ever  ECHO_REPLY
              received  a  backspace  is  printed.  This provides a rapid display of how many packets are being
              dropped.  If interval is not given, it sets interval to zero and outputs packets as fast as  they
              come  back  or one hundred times per second, whichever is more.  Only the super-user may use this
              option with zero interval.