Using Iperf to Measure Network Bandwidth
“iPerf3 is a tool for active measurements of the maximum achievable bandwidth on IP networks. It supports tuning of various parameters related to timing, buffers and protocols (TCP, UDP, SCTP with IPv4 and IPv6). For each test it reports the bandwidth, loss, and other parameters” you need to run one instance on one machine as server and another instance on second machine as client.