Network utilization

Inputting 'n' can get network utilization:

The statistics are read from /proc/net/dev file (processed by proc_net function):

$ cat /proc/net/dev
Inter-|   Receive                                                |  Transmit
 face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed
  eno2:       0       0    0    0    0     0          0         0        0       0    0    0    0     0       0          0
    lo: 61231535   54975    0    0    0     0          0         0 61231535   54975    0    0    0     0       0          0
  eno1: 6123992486 37999646    0 92998    0     0          0    769601 54887394843 48055902    0    0    0     0       0          0

It is not difficult to comprehend meanings of every field (You can refer this discussion).