FortiGate 60E - AWS Config Help?

[aven]

Hi all,

I am trying to setup a VPN IPSec Tunnel between my network at home to my AWS VPC.

There is a router that's holding the public IP address and act as bridge and DHCP server.

My FortiGate 60E is currently sitting behind this router on an IP address that it got from the router.

I have setup the VPC and its VPN on the AWS side and also configured the necessary FortiGate configuration that I downloaded from the AWS side.

My VPN tunnels seems to be still DOWN.

My questions is, I have done some research and I found that a lot of people have their routers doing the NAT so we would need to open port 500 and 4500 on the router side and do some port forwarding. Do I need to open those ports if my router is not doing any NAT, is there anything I'm missing?

Sorry if my question is unclear as I'm new to FortiGate.

Thanks!