Technical Tip: How to perform a traffic test on a FortiGate interface that is using PPPoE as the addressing mode

It is not possible to select the 'ppp' interface when trying to set 'diagnose traffictest client-intf' and 'diagnose traffictest server-intf'.

The example below shows port2 using PPPoE for the addressing mode:

When the interface is in PPPoE addressing mode, the FortiGate creates the 'ppp' interface:

If the 'ppp1' is set for the client-intf and server-intf for the traffictest commands, it will not allow it:

A traffictest will fail, since no IP address is assigned on the Physical Interface (port2). An IP address is assigned to the virtual interface 'ppp':

Solution 1:

Starting from v7, FortiGate can be a Speedtest Server.

Use the following commands to enable this feature:

config system global
    set speedtest-server enable
end

Add 'speedtest' on the interface where PPPoE is the addressing mode:

config system interface
    edit port2
    append allowaccess speedtest
end

It is now possible to run speedtest using iPerf on a machine and point it to the Public IP of FortiGate's PPPoE interface:

Traffic from the iPerf Client for TCP port 5201 is incoming on the 'ppp1' interface:

For this setup, the topology looks like this:

[IperfClient]---------Internet-------------------publicIP [PPPoE-ISP-Router]------------------------10.13.13.255 [FortiGate].

The PPPoE Router is configured to port-forward traffic to 10.13.13.255, which is a private IP.

If the FortiGate has the public IP assigned directly to the PPPoE interface, it is possible to use the Public IP that is attached to the FortiGate's interface. There is no need for port-forwarding on the ISP's PPPoE Router.

Note:

This feature has stopped working from v7.4.3: Technical Tip: Unable to establish an iperf connection with a FortiGate acting as a SpeedTest Server and running v7.4.3

Solution 2:

Configure a PPPoE interface instead of having PPPoE addressing mode on a Physical Interface.

Select the PPPoE interface on the traffic test commands after configuring the PPPoE interface.

Related articles:

Technical Tip: PPPoE-interface configuration.

Technical Tip: Use cases for the diagnose traffictest command.

Troubleshooting Tip: Configure FortiGate as speed test (iperf) server.