The Ubuntu VM is running on an ESXi 6.5 Host and is configured with 2 VMXNet3 adapters.
One of the NICs (within the VM) is configured for Promiscuous mode. The associated vSwitch is tied to a dedicated vmnic and the vSwtich is configured for Promiscuous mode (Accept).
Our application is trying to compute response times and the responses are showing up before the requests for a good percentage of attempts. The difference between the response and request is anywhere between 10 - 100 microseconds. The request and responses are UDP packets.
I ran pktcap-uw against the vmnic attached to vSwitch and I see all the packets show up in the correct order on the physical NIC and the vSwitch. It appears that the Ubuntu VM is unable to retrieve packets in the right order. I have confirmed this by running tcpdump within the Ubuntu VM.