Question
Question
Modem 1 can track activity from Modem 2, but only if both are properly configured and authorized. Ensure proper authentication and that data flows correctly between devices.
I don't want my dad to track my activities, only my service provider.
It varies based on your dad's situation. On my network I can track all your activities or limit access to certain services. Using more routers won't help hide your actions.
Using multiple routers creates problems and complicates port forwarding. You might handle it better with a VPN. Most VPN services can accommodate several devices, usually supporting up to five simultaneously.