WAN to VPN to Router setup

Am having trouble setting up the following config.

Broadband WAN connection into
FVS318 VPN - 8 port to route to non wireless clients
one LAN port of the FVS318 into the WAN port of
WGR614

I tried DHCP off and also on but with a limited range on the downstream (WiFi) router. I also tried setting its WAN IP to fixed (192.168.1.11) and to DHCP and the WGR614 just seemed to no longer respond to connection requests.

So, rather than troubleshoot my trials, what is best practice for how to configure WGR614 as a downstream Wireless router from another router?