3-30 Firmware User Guide
A restriction
Since both the router and the passthrough host will use same IP address, new sessions that conflict with existing sessions will be rejected by the router. For example, suppose you are a teleworker using an IPSec tunnel from the router and from the passthrough host. Both tunnels go to the same remote endpoint, such as the VPN access concentrator at your employer’s office. In this case, the first one to start the IPSec traffic will be allowed; the second one – since, from the WAN it's indistinguishable – will fail.
