Chapter 10 Install and System Administration for FortiOS 5.0 : Interfaces : PPPoE addressing mode on an interface
  
PPPoE addressing mode on an interface
If you configure the interface to use PPPoE, the FortiGate unit automatically broadcasts a PPPoE request from the interface.
The FortiGate units support many PPPoE RFC features (RFC 2516) including unnumbered IPs, initial discovery timeout and PPPoE Active Discovery Terminate (PADT).
PPPoE is only configurable in the web-based manager on desktop FortiGate units. 1U FortiGates and up must be configured in the CLI using the commands:
config system interface
edit <port_name>
set mode pppoe
set username <ISP_username>
set password <ISP_password>
set idle-timeout <seconds>
set distance <integer>
set ipunnumbered <unumbered-IP>
set disc-retry-timeout <seconds>
set padt-retry-timeout <seconds>
set lcp-echo-interval <seconds>
set dns-server-override {enable | disable}
end
Configure PPPoE on an interface in System > Network > Interface. The table describes the PPPoE status information when PPPoE is configured for an interface.
Addressing mode section of New Interface page
Status
Displays PPPoE status messages as the FortiGate unit connects to the PPPoE server and gets addressing information. Select Status to refresh the addressing mode status message.
The status is only displayed if you selected Edit.
Status can be any one of the following 4 messages.
 
Initializing
No activity.
 
Connecting
The interface is attempting to connect to the PPPoE server.
 
Connected
The interface retrieves an IP address, netmask, and other settings from the PPPoE server.
When the status is connected, PPPoE connection information is displayed.
 
Failed
The interface was unable to retrieve an IP address and other information from the PPPoE server.
 
Reconnect
Select to reconnect to the PPPoE server.
Only displayed if Status is connected.
User Name
The PPPoE account user name.
Password
The PPPoE account password.
Unnumbered IP
Specify the IP address for the interface. If your ISP has assigned you a block of IP addresses, use one of them. Otherwise, this IP address can be the same as the IP address of another interface or can be any IP address.
Initial Disc Timeout
Enter Initial discovery timeout. Enter the time to wait before starting to retry a PPPoE discovery.
Initial PADT timeout
Enter Initial PPPoE Active Discovery Terminate (PADT) timeout in seconds. Use this timeout to shut down the PPPoE session if it is idle for this number of seconds. PADT must be supported by your ISP. Set initial PADT timeout to 0 to disable.
Distance
Enter the administrative distance for the default gateway retrieved from the PPPoE server. The administrative distance, an integer from 1‑255, specifies the relative priority of a route when there are multiple routes to the same destination. A lower administrative distance indicates a more preferred route. The default distance for the default gateway is 1.
Retrieve default gateway from server
Enable to retrieve a default gateway IP address from a PPPoE server. The default gateway is added to the static routing table.
Override internal DNS
Enable to replace the DNS server IP addresses on the System DNS page with the DNS addresses retrieved from the PPPoE server.
When VDOMs are enabled, you can override the internal DNS only on the management VDOM.
See Also
• Interface settings
• Administrative access
• DHCP addressing mode on an interface