Sorry for the dumb question and hopefully this is relevant enough to the sub. I have my own firewall and right now it connects to my ISPs provided home router over rj45, their router gets a fiber hookup to their network and it’s the only ISP device in my home. If I have a firewall with a fiber port, can I take the fiber to the modem and hook that straight to my firewall, or is there a reason I need their device?