VMs share the same network interface. For example, if we run 3 VMs: VM1, VM2 and router, then we see network interaction VM1<->VM2 twice: VM1<->router and router<->VM2.
This can be seen as TCP Retransmission and some users find it confusing:

To make the pcap look cleaner, let's either filter the retransmissions out from the pcap or change the infrastructure, so that VMs are physically detached from each other.
VMs share the same network interface. For example, if we run 3 VMs: VM1, VM2 and router, then we see network interaction VM1<->VM2 twice: VM1<->router and router<->VM2.
This can be seen as TCP Retransmission and some users find it confusing:

To make the pcap look cleaner, let's either filter the retransmissions out from the pcap or change the infrastructure, so that VMs are physically detached from each other.