Virtualization makes it possible to separate vital network functions on different systems without purchasing additional network adapters for each one. What is the drawback?

Once the single network adapter crashes, all virtual machines fails.

Explanation:

Virtualization in computer networking system is the configuration of virtual machines (VM) on a host operating system in a computer.

A computer system running an operating system can support multiple virtual machine configuration. It reduces the cost of purchasing computer systems or even network card adapter and different operating systems can run on different virtual machines.

Using one network card to run multiple VMs can be detrimental, because when the network adapter fails, all the virtual machines configured also fails.