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}


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.



The interface retrieves an IP address, netmask, and other settings from the PPPoE server.

When the status is connected, PPPoE connection information is dis- played.


Failed                                The interface was unable to retrieve an IP address and other inform- ation from the PPPoE server.



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.


Addressing mode section of New Interface page



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.

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