For VPN purposes, whether the VPN is used would depend on which wireless connection is being used. With this setup, devices connected directly to the CNG3 would not use the VPN and devices connected to the Asus RT-n65u would. It's good to have that choice since, depending on the setup, the VPN may cause problems with some web sites. I would turn the router off in the CNG3 , use the Asus RT-n65u as a non-VPN wireless access point and plug the WRT-54GS into the second PC NIC as a VPN wireless access point. It might be necessary to upgrade the WRT-54GS if many wireless devices are use concurrently.