Spirent TestCenter Virtual.
Case 1 :
Make sure if we change the number of ports, the additional virtual NICs need to be added under the VMware edit settings dialog. We need to make sure that the number of vmxnet3 NICs equal the number of test ports.
Case 2 :
ESX5.5 with Spirent TestCenter Virtual version 4.33 and 4.38 had an issue whcih is resolved with 4.40