Type 1 Hypervisor:This is also known as Bare Metal or Embedded or Native Hypervisor. It works directly on the hardware of the host and can monitor operating systems that run above the hypervisor. It is completely independent from the Operating System. The hypervisor is small as its main task is sharing and managing hardware resources between different operating systems.A major advantage is that any problems in one virtual machine or guest operating system do not affect the other guest operating systems running on the hypervisor.
Type 2 Hypervisor: This is also known as Hosted Hypervisor. In this case, the hypervisor is installed on an operating system and then supports other operating systems above it. It is completely dependent on host Operating System for its operations.
A virtual machine, commonly shortened to just VM, is no different than any other physical computer like a laptop, smart phone or server. It has a CPU, memory, disks to store your files and can connect to the internet if needed. While the parts that make up your computer (called hardware) are physical and tangible, VMs are often thought of as virtual computers or software-defined computers within physical servers, existing only as code.
Here are a few ways virtual machines are used:
Building and deploying apps to the cloud.
Trying out a new operating system (OS), including beta releases.
Spinning up a new environment to make it simpler and quicker for developers to run dev-test scenarios.
Backing up your existing OS.
Accessing virus-infected data or running an old application by installing an older OS.
Virtual routing and forwarding (VRF): VRF is an IP-based computer network technology that enables the simultaneous co-existence of multiple virtual routers (VRs) as instances or virtual router instances (VRIs) within the same router. One or multiple physical or logical interfaces may have a VRF but none of the VRFs share routes. Packets are forwarded only between interfaces on the same VRF.
IPSec uses authentication Header (AH), and Encapsulating Security Payload (ESP) protocols for transporting packets securely over the Internet. Note that PPTP and L2TP are tunneling protocols, where as IPSec provides strong encryption.
The two primary security services that are provided by IPSec are:
Authentication Header (AH), and
Encapsulating Security Payload
AH provides the authentication of the sender, and ESP provides encryption of the payload.