I've spent an entire day trying to follow the steps laid out in the following thread for chaining two networks together in PPPoE configuration: link
I'm trying to put the modem in "dumb" mode to bypass the double NAT issue between my modem and router so that I can use my router to manage port forwarding for remote access to devices on the LAN (PCs, printers, NAS, & security cameras).
The RT-AC66U is assigned 192.168.0.3 from the modem, but is referenced as 192.168.1.2 on the office LAN.
My modem's LAN IP address is 192.168.0.1 and subnet mask is 255.255.255.0. My modem's ISP-provided IP is dynamic.
I tried turning the modem's DMZ on, NAT off, DHCP off, AND adding a Static Routing rule of: Subnet IP: 192.168.1.2
Subnet Mask: 255.255.255.0
Gateway IP: 192.168.0.3
Then, I changed the WAN type of the Asus router to PPPoE, manually added 192.168.0.1 as the Primary and Secondary DNS server addresses, and entered in my ISP username and password. Unfortunately, it didn't work, I had no internet access, and when I tried to navigate to the modem's configuration menu I was getting routed to back to an error message (about no connectivity) on the router's configuration menu. So maybe I got close? I took me quite a while to reverse my changes via a mobile hotspot.
If anyone is willing to point me in the right direction, I would be forever grateful.
Additionally, I've been trying to work off of the linked resources below: link link link link
Insure that your Actiontec is making an Internet connection by attaching a computer. Then disconnect the computer and then connect an Ethernet cable from the Actiontec to the WAN port of the AC66U, make the Actiontec address (192.168.0.1) the WAN address in the AC66 and use a different subnet for the AC66 LAN (like 192.168.1.1). If you need to use any static addresses in your LAN leave a few available (say 192.168.1.2 - .10) and set the AC66 DHCP range from 192.168.1.11-.254. Have all of your devices automatically obtain an IP address and they will get it from the AC66.
Don't connect anything but the AC66 to your Actiontec.