Chapter 1: Understanding Lans

The correct answer is "Two or more computers that exchange data". This answer accurately defines what a network is - a collection of interconnected devices (such as computers) that communicate and share data with each other. Networks can be wired or wireless, and they enable users to access shared resources, such as files, printers, and internet connections. By connecting multiple computers together, a network allows for efficient communication and collaboration between users.

A byte consists of 8 bits. This means that there are 8 bits in a byte.

Centralized computing uses a supercomputer. In centralized computing, all the processing power and resources are concentrated in a single location or server, which is typically a supercomputer. This allows for efficient and powerful processing capabilities, making it suitable for tasks that require massive computational power, such as scientific research, weather forecasting, and simulations.

A network topology refers to the physical layout or structure of a network. It defines how devices or hosts are physically connected to each other and to the network. This includes the arrangement of cables, switches, routers, and other networking devices. The physical connection of hosts to the network determines how data is transmitted and received between devices. Different network topologies, such as bus, star, ring, or mesh, have varying physical connections that impact the efficiency and reliability of the network.

A three-leg perimeter network typically consists of three separate networks or zones: an internal network, an external network, and a DMZ (demilitarized zone). In this setup, there is usually only one firewall that separates the internal network from the external network, providing security and controlling the traffic flow between them. Therefore, the correct answer is one.

A perimeter network, also known as a demilitarized zone (DMZ), is a network that is set up outside of a company's LAN. It acts as a buffer zone between the company's internal network and the external network, providing an additional layer of security. It typically contains servers and services that need to be accessed by external entities, such as web servers or email servers. By placing these resources in the perimeter network, it helps to protect the internal network from potential threats and attacks.

A hub is the most basic connecting device because it operates at the physical layer of the network and simply broadcasts all incoming data to all connected devices. It does not make any decisions or perform any intelligent routing like a router or layer 2 switch. A hub is a simple device that allows multiple devices to be connected to a network, but it does not have any advanced features or capabilities.

The most common type of network topology is the star topology. In a star topology, all devices are connected to a central hub or switch, which acts as a central point of communication. This topology is widely used in Ethernet networks as it provides better performance, scalability, and ease of troubleshooting compared to other topologies. In a star topology, if one device fails, it does not affect the rest of the network, making it highly reliable.

A VLAN, or Virtual Local Area Network, is a group of hosts that act as if they are on the same switch regardless of their physical location. This means that hosts in the same VLAN can communicate with each other as if they are connected to the same switch, even if they are physically located in different areas or connected to different switches. VLANs provide network segmentation and improve network performance, security, and manageability.

Computers on Ethernet networks use frames to communicate. Frames are the basic units of data transmission in Ethernet networks. They contain the source and destination addresses, as well as the actual data being transmitted. Frames are used to ensure that data is properly transmitted and received by the intended recipient.