A Router with a static IP can be connected to a network interface configured to the type "DSL/Router". The Intra2net system then routes the IP packets directly to it.
Enter the external IP of the Intra2net system in the configuration under "Local IP". This must be in a network together with the router IP. It must not overlap with the local network or one of the locally routed networks (see Section 9.9, „Intranet Routing“).