How do virtual machines communicate over a network?

Virtual machines communicate over a network primarily by using virtual network cards or adapters. These virtual network interfaces function similarly to physical network cards found in traditional computing environments. Each virtual machine is allocated at least one virtual network adapter, which allows it to send and receive network traffic just as if it were using a physical card.

When virtual machines are configured within a virtualized environment, these virtual network adapters connect to virtual switches, which facilitate communication between VMs on the same host or across different hosts. This method enables efficient network operations without requiring direct physical connections, making it easier to manage and scale virtual infrastructures.

In contrast, relying exclusively on physical switches does not consider the virtualized nature of the environment or the need for flexibility offered by virtual components. Connecting directly to the Internet bypasses the necessary internal networking, which is essential for communication between virtual machines. Finally, while gateways can play a role in routing traffic, they are not the sole means by which VMs communicate over a network. Virtual network cards are fundamental to enabling this communication effectively.