@sonaric, the ISP has information on how I can configure it in bridge mode. The question is whether I need to do it or not :)

@KJK, thanks for the feedback. Modem is a Technicolor TG789VAC v2

@KJK, unfortunately does not support static routing. The only things you can do is Port Forwarding and Firewall rules. No VLAN or Routing options.

@sonaric, thanks for the information. Not sure about the modem or how to check. I have an ONT device for fiber, which goes into a Technicolor modem/AIO device.

Thank you both for the input. In this case, I guess I should be fine if I get something like the ER605 to start with? If yes, then do you recommend / do I need to bridge the ISPs modem/router or is...

@sonaric Yes, trying to use the layer 3 features, and the more I work on it, the more I think that I should have simply gotten a L2 switch and installed a dedicated firewall (thinking of pfSense)...