@barrolete: thank you for your response, and that makes sense. It also sounds like I will still have double NAT even if I use the DMZ function on the ER8411 router for the one PC that I need VPN...

Hello, Would appreciate any solid advice as to whether or not using one-to-one NAT could eliminate double NAT to solve a VPN connection issue, or if one-to-one NAT is still NAT, leaving the issue of...