How do VMs communicate with each other in a virtualized environment?

In a virtualized environment, virtual machines (VMs) primarily communicate through virtual switches configured on the same ESXi host. Virtual switches act as a virtual representation of physical switches, allowing VMs that are connected to the same virtual network to send and receive data packets to and from one another. This virtualization layer facilitates interaction without the need to route traffic through the external physical network.

Using virtual switches promotes efficient intra-host communication, as data packets do not need to leave the host system or traverse external physical networks, minimizing latency and improving performance. Every VM can be associated with a virtual NIC (Network Interface Card), which connects to these virtual switches, enabling seamless network communication just as if they were connected via a physical network.

In contrast, the other options do not provide the optimal or correct method of VM communication in a virtualized environment. Directly using the physical network adapter would not be efficient and would involve unnecessary overhead. Relying solely on the operating system's network stack would still require underlying network infrastructure like virtual switches to facilitate the communication between VMs. Establishing direct connections between virtual disks is not a feasible method for enabling network communication, as disks are primarily for storage rather than networking functions.