With this video, you’re going to learn how to connect your FortiGate unit’s internal (wired) and wireless networks to the internet, with NAT Mode using PPPoE. PPPoE is an alternative to DHCP that some ISPs use, that uses a single IP, username and password received from the ISP to allow access to the internet. Your ISP will inform you if PPPoE is required.
Cookbook – Installing Dual Internet
How to install a redundant internet connection on the FortiGate.