I myself have not tried use DI-704P gateway router. But I have done some search for that router, got following information:
"The DI-704P provides special pass through function for common VPN implementations including PPTP (Point to Point Tunneling Protocol), L2TP (Layer 2 Tunneling Protocol) and IPSec"
Our concentrator support "IPSEC over UDP" and "IPSEC over TCP" function, so as far as DI-704P support normal NAT ( I am pretty sure it does), we can use VPN 3000 and Cisco VPN client this special feature to make mutilple VPN clients passing through the DI-704P router to connect to remote VPN 3000 concentrator.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...