How i can benchmark IPFS with multiple nodes in a IPFS private network

Hi, i need a little help, i want to test the IPFS benchmark from the point of view of throughput in a private or public network. I build a private network thanks to virtualBox with 4VM that there are connected each other with an IPFS private network (3 of them have js-implementation and 1 has go-implementation) , now i want to test the throughput of IPFS in particular I would analyze how the download speed increases when there are more peers to share the same file. I see that there are tools for testing IPFS such as (, for my target is good this tool? I already installed this tool but as i can see it actually doesn’t test in my private network because the bandwidth usage in all the node are 0 mb/s during the test, and when i
switch off the machine of the test still going. I obviously isolated the network of VM from the net thanks to VirtualBox setting the network as" internal network" and removed all the elements inside the bootstrap(there are only the peer that i connect to in the private network). So my question is how i can benchmark IPFS with multiple node?
I thank you in advance for the replies and I apologize if I haven’t been very clear