@tapo_user2022 No, that's not possible. When port forward in a TP-Link home routers it will allow access to this port from any external source.

@SEBAST1AN I've never tested this but you could: Here's an example for configuring 802.1Q VLANs on easysmart switches (I assume you have TL-SG108E).

@RickMo As I think of the ER605 WAN ports IP addressing, If you set ER605 WAN1 and WAN2 with different IP addresses within the 192.168.100.0/24 subnet this might work as expected.

@SamSavage Have you tried to set TL-WA801N LAN IP address as "Static IP" instead and then disable its DHCP server:

@RickMo If the IP addresses are the same this could be a problem since the ER605 wouldn't know how to load balance between the two ISPs. A workaround would be to use the Starlink router in bridge...

@konstantinosdms This would be possible only if you have a full cooperation from ISPs in your country and the "new owner" didn't change its WAN MAC address. Not to mention that if the "new owner"...