ZyXEL Communications ZyWall 35 Support Notes page 136

change at least one of the LAN IP addresses in order to prevent the routing problem. Unfortunately,
changing the entire network setting takes extra effort in configuration, which is never preferable.
The feature enhancement named "NAT over IPSec" is designed to resolve the IP network overlapping
problem without changing the original network architecture.
In order to achieve this application, you are required to configure the side ZyWALL devices according to
the following procedures: (Assumption: We call "My ZyWALL" ZyWALL 1 and "Remote Gateway"
ZyWALL 2.)
Configure network setting on ZyWALL1 and ZyWALL2 according to the network
topology as planned.
Create the IPSec Gateway Policy on ZyWALL 1 and ZyWALL2
Create the IPSec Network Policy on ZyWALL 1 and ZyWALL2
Trigger the IPSec VPN connection between ZyWALL 1 and ZyWALL2
Verify the functionality of NAT over IPSec via. Ping command
STEP 1: Configuring the Network Setting on the ZyWALL 1 and ZyWALL 2
Lunch a web browser window and logon into the ZyWALL's web configurator. Configure the LAN and
WAN interfaces according to the application scenario and network topology you planned. Configure both
of the ZyWALL's LAN and WAN interface with the proper IP address and network mask.
ZyWALL 1 (Local)
All contents copyright (c) 2006 ZyXEL Communications Corporation.
ZyWALL 35 Support Notes
136