Internet <---> 320B (ADSL modem) <---> Fortigate 60 (firewall) <---> lan
The ADSL line is with static IP, with username and password and with pppoa.
The web interface of the DSL 320B allows only 3 configurations: 1. with dynamic IP, username and password 2. with static IP, without username and password 3. bridging without username and password. The Fortinet Fortigate 60 allows only connections with pppoe, so it seems that the third config couldn't work. The first also, because I have a static IP and the second doesn't work because I have to give username and password to authenticate the connection.
Maybe I could solve the problem with the cli of 320B, but it's fully undocumented and till now I couldn't find documentation.
With this ADSL line config and with this hardware is it possible to solve my problem?
From the info above, I would say 'No'.
Given the cost of the Fortigate box, and the ADSL box (pretty expensive, dirt cheap) wouldn't it make more sense to buy a new ADLS modem that suits?
The way we ran our office was with a Fortigate box. Well, multiple offices, multiple boxes, globally to build a large WAN through permanent VPNs between sites. The FortiGates worked really very well, high uptime, and good throughput. Certainly not consumer grade, which the adsl modem really is.
So, I would find a half-decent ADSL modem (NetGear etc), and configure it to connect for you and get the IP, bridging the connection to the WAN port of the Fortigate, which can then handle NAT, DHCP, etc.