What is the procedure to use all the IP addresses for the Zywall/USG?
Step by step guide
1. Setup of your physical WAN interface.
2. Use the virtual interface feature to add a WAN interface.
3. Specify the additional public IP and ensure that it is in the same subnet as the physical WAN interface.
4. The virtual interface will be displayed, as shown in the screenshot.
You can ping both public IPs and get an answer from both of them, the physical and virtual interface.