From time to time my ISP randomly add’s NAT service to my account, and since I have it built in on my router as well I am getting all sorts of double NAT issues preventing access for some services.
I’d like to be able to detect and get notification as soon as this situation occurs (would save me some precious hours of investigation till I reach that conclusion myself…)
I am sure others would benefit from this as well
You can google “Double NAT issues” or check out the following post including ways to identify it - I think that would be a classic sensor module for HA.