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I have fiber coming in from a new ISP which is being handed off via Ethernet on a single physical port. I'm having doubts about how to approach the configuration on my FortiGate 200A firewall because I've been given a /30 containing the ISP's gateway and another /28 for external IPs I can use:

x.y.76.12/30 (.13 is the GW)
x.y.76.64/28 (public IP space)

How do I configure the FG200A's WAN1 interface to be aware of the two networks? As I only have one physical ISP port, will I need to plug it into a switch to break-out two cables and use a DMZ port on the FG200A for setting up the /28? Thanks in advance for your insight!

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You don't.

Configure the WAN interface with only the /30. Then configure the DMZ interface with the /28. Your ISP should route the /28 to your x.y.76.14 address. Enable security policies to allow traffic to flow between the two security zones.

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Thanks. Turns out the FG200A was able to use the IPs once I set them up and configured access policies (ARP). – slyderc Oct 9 '12 at 19:30

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