Gargoyle with Sagecom F@ST3864V3AC

[focus]

My internet provider (Optus) forces us to use a crappy Sagecom F@ST3864V3AC router and I would like to use Gargoyle instead.
I have previously successfully done this but while I was away Optus came to my house and replaced their modem and ruined my setup. I am now struggling to make the internet work when using Gargoyle.

Is there a detailed guide on how to set this up or can someone please provide their settings?

[Lantis]

Without additional information about the type of connection you have, it is likely you’ll need to use DHCP wired as the connection type and ensure that there is no conflict between the ip ranges of the Optus and Gargoyle routers.

If you’re on an NBN connection it is unlikely you can fully eliminate the Optus device depending on connection type