How to track traffic from a site mirror?

Question

Computer networks

The question, I think, is simple, but Google didn’t help to find the answer)
The situation is as follows, there is the main site.ru domain, it has a 301 redirect from the site.rf domain.
Actually, how to count clicks on 301 redirects to the main domain, if there is no way to put a metric on the site.rf mirror? And if you manage to deliver, will there be traffic fixation?

Answer 1

Set the metric to the main one and see where people came from.
It would be more correct to look at the logs on the mirror with a 301 response.

Answer 2

Stupidly look at mirror logs and see all traffic