Technical Tip: Specifying a source IP while doing an iPerf test from the FortiGate

When doing an iPerf test from the FortiGate, by default it will use the IP of the egress interface as the source IP.

In some cases (especially when over a VPN tunnel doing BGP), this source IP will not be routable and the iPerf test will not connect.

Here is an example of the command in the default state:

It uses the default address of the configured interface, in this case, port9:

To specify a source IP, use the '-B' flag when running the iPerf command. For example:

diag traffictest run -c x.x.x.x -B y.y.y.y

It is also possible to see this source IP in the sniffer:

Note:
Refer to the iPerf CLI Reference for more granular controls over the iPerf test.