I bought an Amazon Eero 5 Pro last year with the intention to use the Smart Queue Management (SQM) technology on the router. In order to get this router setup with my broadband I needed to buy a TP-Link TD-W9970 to act as the modem as I have a PPPoE connection that the Eero is not compatible with.

Unfortunately this setup is causing a double NAT issue which has been making downloads fail and 4K streams to hitch consistently. I am fairly sure it is double NAT because using the Eero in bridge mode solves the issue and connecting straight to the TD-W9970 also solves the issue. Using the Eero in bridge mode is not an option as this removes the ability to use SQM. It is not an option to put the TD-W9970 into bridge mode either as the broadband connection with the ISP is lost and the Eero does not support PPPoE unless I upgrade to the Eero 6.

I have tried using DMZ on the TD-W9970 forwarding to the Eero but I still have double NAT so I’m not sure if the DMZ is working/setup correctly. Any ideas?