Currently, before launching the production cluster, i run 'iperf -s' on half of the cluster and then run 'iperf -c $nextIP' on the other half using parallel ssh, So simultaneously all cluster's nodes are connecting together (paired) and then examining the result of iperfs, doing the math that if the Switches could keep up with Cassandra load or not? I'm afraid that i do not determine usual packet size of Cassandra and in real scenarios each node is streaming with many other nodes Any better idea on examining network before running a cluster? Sent using Zoho Mail