Stress test unmanaged network switch

Hi - I have a 5 port unmanaged network switch that is going to be in a mission critical application in awful environmental conditions (-30 to +70C). The switch is rated for these temperatures, but to prove this I'm going to put it in a thermal chamber and cycle it for quite awhile.

During this test I would like to run maximum data through each of the five ports to see if any packets are dropped / a port fails intermittently.

Is there a tool that would let me test all ports simultaneously and monitor the traffic through them? How would you go about doing this?

Thanks for your help!