Got this from their support team: Hello and thank you for contacting TP-Link support. Upon checking your configuration screenshot, we found that your WAN IP is a private IP so you cannot set port...

@Yannie I don;t think I'm running the controller. The web interface to my router also looks very different from your screenshots. I don;t see where I can enable Layer-3.

No luck. I wonder if I need to do a firmware update...

Here's the situation: I use the business router (ER7206) inside my LAN to create an isolated "sub" LAN. The setup goes like this: - Brand new out of the box (which means many default settings are in...