VM's talking to each other on the same hypervisor

Lets say I have 2 guest machines, and they try to talk to each other via the network card. When machine 1 sends a packet, machine 2 is not active in that slice of time. Wouldn't machine 2 miss seeing that packet or part of the packet ?

 

see here.

 

In particular, I want to see if I can run pfSense and another Linux on the same host. pfSense vm generates Netflow and the Linux vm captures it. Would the Linux vm be able to capture ALL netflow data or will it be not able to see them because pfSense vm is running at the 'same time' as the Linux vm? I suspect the Linux vm will not be able to receive the netflow data.

 

i believe it's doable but don't know how to do it. it requires a lot of work.