(interface-statistis interface)
This procedure returns a dotted pair of two numbers, the car component reports the number of packets received, the cdr component the number of packets reported to be dropped. On macOS the number of dropped packets is absolute, whereas on Linux the number of dropped packets is reset to 0 after each retrieval.
> (define i (interface-attach "en0")) (interface-statistics i)
i
> (0 . 0)
> (interface-statistics i)
(5365 . 5353)
>