If your external IP at home changes then you wouldn’t be able to continue to get this info, right? Not unless you also set up some sort of dynamic DNS.
If your asking about Tasker on the tablet pinging phones? I gave the tablet and all the phones static IP on my network. So when the phones came home, connected to WiFi, the tablet ping will get a reply. Tasker sets virtual switch that phone is home.
Opposite true when they leave. Problem is the IPhone WiFi goes to sleep so not reliable.
But a PC network card should be able to stay able wake and reply.