Apologies if I’m coming at this from the wrong angle but currently we have a Mikrotik that acts as a full router/firewall and it connects to the internet using PPPoE and it assigns the WAN IP via DHCP. We are looking to replace all the Wifi with Eero.
The problem is Eero does not support PPPoE so I wondered if I could repurpose the Mikrotik to just perform PPPoE and nothing else (no firewall/NAT/WiFi etc). The Mikrotik would sit between the ISP and Eero, the Mikrotik would make the PPPoE connetion and the Dynamic IP provided by the ISP would be applied to the Eero WAN interface. Is this possible? If so, how?
I appreciate the Eero can be put in bridged mode but I do not wish to lose the advanced functionality that happens by doing so. I also want to avoid double NAT.
Are you sure your Mikrotik currently gets its WAN IP address using DHCP? PPPoE is a flavor of PPP, which means that the IP address is not assigned to the client using DHCP but using a protocol from the PPP suite (IPCP in particular). The PPPoE interface is normally an L3 one, unless both the client and the server support BCP for L2 tunneling; if they do, you could have an L2 tunnel terminated on a bridge interface on the client, and a DHCP client attached to that bridge; is that the case?
If yes, just detach the DHCP client on the Mikrotik from the bridge, make one of its Ethernet interfaces a member port of that bridge, and connect the Eero WAN to that Ethernet interface, with its own DHCP client enabled on WAN.
If not, there is no way to let the ISP assign the IP address directly to the Eero WAN, but you may be able to avoid double NAT by letting the Mikrotik do the NAT job and route traffic for Eero’s LAN subnet(s) to the Eero if NAT can be deactivated on the Eero.
If you are not sure, show the current configuration of the Mikrotik.