Chapter 10 - Virtual Networks and Remote Access

In this chapter we learned about Virtualization. Very simply it is the emulation of a computer on a physical system. It also could be of an operating system or an application. Virtualization offers many advantages such as:

• Efficient use of resources
• Cost and energy savings
• Fault and threat isolation
• Simple backups, recovery, and replication

However some disadvantages are:

• Compromised performance
• Increased complexity
• Increased licensing costs
• Single point of failure

 Virtual networks can consist of virtual machines on a physical server. More common are networks that combine physical and virtual elements. Virtual network components include a virtual adapter or vNIC which is required to connect to a network. Virtual bridges or ports on a switch connect to vNICs with a network, whether virtual or physical. A virtual switch is a logically defined device that operates at the data link level to pass frames between nodes. Network connection types include bridged (physical network using the host machine NIC), NAT (relies on the host machine to act as NAT device), and host-only (exchange data with each other and host only).

The text covers remote access and virtual computing through the following methods:

• Dial-up Networking
• Remote access servers
• Remote access protocols
• Remote virtual computing

 The chapter speaks to Virtual Private Networks (VPNs) which are wide area networks that are logically defined over public transmission systems. It concludes with cloud computing (see below) which refers to the flexible provision of data storage, applications, or services to many clients over a network.

I found the material to be very informative but yet concise. There were a lot of good diagrams and illustrations to help make key points.