Thank you very much for your reply. Now I know it is not possible and I will continue to use the WAN port for this purpose. I was trying to get as much LAN ports as possible so I don't have to add...

I have established unencrypted PPTP VPN tunnel successfully from my TL-R600VPN to a commervial VPN provider PureVPN. I'm trying to treat this PPTP tunnel as WAN and route internet traffic from a...