How to test switches?

Question

network hardware

The other day I bought a used L2 switch in addition to the home one, ran a 10 GB file from the server through it, loaded it back, everything was fine, put it in the rack, configured the VLAN and forgot. Within a few days, I began to notice that network performance dropped, and if the traffic goes not through the new switch, but through the cisco sg200 (old), then everything is fine. And now the question itself is how to test switches, what methods, applications, or hardware testers are there for this?

Answer 1

Iperf on the one hand the server, on the other hand the client and load it with traffic.