The operating system agnostic PXE network booting environment is simulated, such that the VMs boot “virtually” from a network boot image, which is actually provided by the hypervisor. More specifically, the network traffic of VMs is filtered, and PXE requests are detected. Responsive to a detected PXE request, the hypervisor simulates the PXE server, and returns an invalid IP address to the VM for PXE communication. This invalid IP address is configured for only internal communication on a virtual network. The hypervisor intercepts PXE related communication sent by the VM to the invalid address, and returns expected PXE responses to the VM, including a boot image. This allows the hypervisor to provide, inspect and/or modify the boot time environment of VMs.