(linux)

vnstat -l -i p4p1

root@suri:/var/# vnstat -l -i p4p1
Monitoring p4p1...    (press CTRL-C to stop)

   rx:    13.24 Mbit/s  7162 p/s          tx:        0 kbit/s     0 p/s^C


 p4p1  /  traffic statistics

                           rx         |       tx
--------------------------------------+------------------
  bytes                   242.14 MiB  |           0 KiB
--------------------------------------+------------------
          max           23.23 Mbit/s  |        0 kbit/s
      average           14.59 Mbit/s  |     0.00 kbit/s
          min           10.83 Mbit/s  |        0 kbit/s
--------------------------------------+------------------
  packets                     898049  |               0
--------------------------------------+------------------
          max               8056 p/s  |           0 p/s
      average               6603 p/s  |           0 p/s
          min               4798 p/s  |           0 p/s
--------------------------------------+------------------
  time                  2.27 minutes

root@suri:/var/#

freebsd
systat -if
netstat -w1