Dear @Hugo_Saraiva,

Hugo_Saraiva wrote
In the last few days I changed my GPON 100/20 Mbps Internet access to a 500/100 Mbps enterprise solution.
Since the access is gigabit, I bought an ER7206 router. The ISP router was going to DMZ to the ER7206's IP but since there have been speed issues the carrier can't resolve, the alternative is to connect the TP-Link directly to the fiber ONT. As it turns out, we were able to get the previous Draytek Vigor 2920vn working with 100 Mbps speed limit but not the ER7206 in the same way.
The ISP uses a gateway between the public IP and the client, even though my access has a public IP assigned.
So we have to put a Fixed IP and a gateway given by them in the WAN configuration and then assign an Alias IP on the WAN (this in Draytek), then do a Routing Policy (source IP to Any destination IP, ater that we select the wan Interface, and then the Alias/ public IP of the WAN).
In the ER7206 I can get it working but with one-to-one NAT, the speed is 502/102 Mbps, but it will force me to map all the internal addresses, not counting the WIFI devices that will connect. I also had another problem that I can't connect LTP2 or PPT clients to the router with windows client access that are outside the network, which I did without problems with the Draytek and do on other company networks where I have other Omada ER routers, I have 3 more buildings far away, total of 4.

It currently can not set WAN IP Alias on the ER7206, so it may not be able to meet your needs.

In addition, DMZ has a higher priority than VPN, so you can choose to use a device without DMZ as a VPN Server.

Best Regards!