@lucky99eu I did some tests and it is possible to create 2 different VLANs and leave them untagged. VLAN1 with IP 192.168.0.1 to do NAT and VLAN2 with IP 100.100.100.1 to use as default gateway of...

@lucky99eu for the VLAN question, I was hoping we could add another new vlan but always with VID 1 in order to add a second different IP, instead an error tells to us that the VID must be different....

@lucky99eu many thanks for the answer, your explanation is perfect but this way I had already considered it. Actually I expressed myself badly, I'll explain the scenario better using your example...

The provider gives me an additional subnet with 8 public ip on the WAN side (connected with PPPoE) and I have to configure it in the router. I don't use the first and last one but the second must be...