It seems that the router is not resolving the Dynamic DNS address and therefore not giving me the option to connect the VPN. The trick for dynamic-to-dynamic: First set up dynamic dns and make sure it works. (go to Setup - DDNS in firmware 1.3.x, Setup - Dynamic DNS in 4.x) Here are the important parts: Click VPN. Give the tunnel any name- don't use spaces (earlier versions would fail with a space, I don't know if 4 does or not) Make sure the interface is a working WAN interface.
Does a Gateway to Gateway VPN work with Dynamic IP addresses on each end? In Remote gateway Security Type select Dynamic IP Domain Name (FQDN) Authentication, the page will refresh.
exit You can specify DDNS or HTTP but not both in one step.