Technical Tip: How to configure PPPoE interface when ISP provides only VLAN ID

[jsarah]

Description	This article describes how to configure the PPPoE interface in FortiGate if the ISP does not have an IP but just a VLAN ID.
Scope	Firmware v7.0 and above.
Solution	Step 1: Create a VLAN interface/sub-interface under the required physical interface. Follow the following KB article for creating VLAN-tagged sub-interface: Technical Tip: How to create a VLAN tagged interface (802.1q) on a FortiGate - tagged/untagged traff... Make sure to select the role of the interface as WAN. Example of configuration command in CLI: config system interface     edit "pppoe"                                               <-- Name of sub-interface.         set role wan                                       <-- Always select role WAN.         set interface "port3"                         <-- Bind it to the required physical interface, port 3 is used as an example.         set vlanid 20                                     <-- Mention the VLAN ID that the ISP has been given. 'vlanid 20' is used as an example.        next end Step 2: Configure PPPoE configuration commands as shown below: config system interface     edit "pppoe"         set vdom "root"         set mode pppoe         set username "<xxxxxx>"           <-- Provide the username.         set password "<yyyyyy">           <-- Provide the required password.     next end Starting FortiOS v7.4.7 and above, the PPPoE option is available on GUI by default. Also, configuration will be retained in case the addressing mode is set to other modes then back to PPPoE. To configure, go to Network -> Interface -> Create New -> Interface. By default, the 'Retrieve default gateway from server' is enabled. This will automatically populate the default route for the PPPoE interface. To modify the distance and priority, refer to the article: Technical Tip: Changing Distance and Priority of Default Gateway Learned from PPPoE To troubleshoot issues regarding PPPoE, follow this article: Technical Tip: Troubleshooting PPPoE connection failed. Related articles: Technical Tip: How to create a VLAN tagged interface (802.1q) on a FortiGate - tagged/untagged traff... Technical Tip: PPPoE-interface configuration Technical Tip: Troubleshooting PPPoE connection failed