MASQ VPN to VPN Router
 

I'm trying to setup a VPN tunnel from a machine behind my iptables router to a VPN router and I cannot get it to work correctly.

When I attempt to ping any machine inside the VPN Router it just pings Negotating IP Security for hours on end.

Is there some prerouting or 'incoming' ports that need to be allowed?

eth0 internal network, eth1 external network