Computer networks, Protocols and Layers Test

State two differences between a WAN and a LAN.

• A WAN uses third party cabling / leased line to transfer data between geographically remote sites. A LAN uses cabling owned by the company using the network. LANs are typically spread over a small area such as building or home.

• A WAN uses cabling owned by the company using the network. LANs are typically spread over a large area such as a city or country.

Which of the following statements is true?

• The World Wide Web uses the Internet to transfer data.

• The Internet is an example of a WAN.

• Every networked device in the world has a unique IP address.

• Every network interface card has its own unique MAC address.

How does a DNS server help in accessing a website given the address the user has entered?

• DNS servers use a database of website addresses and their corresponding IP addresses; a website address that is entered is looked up in a DNS database to find the matching IP address.

• DNS servers use a database of website addresses and their corresponding IP addresses; a website address that is entered is looked up in a DNS database to find the matching MAC address.

• DNS servers use a database of website addresses and their corresponding IP addresses; a website address that is entered is looked up in a DNS database to find the matching URL.

• DNS servers use a database of website addresses and their corresponding IP addresses; a website address that is entered is looked up in a DNS database to find the matching domain name.

What is one advantage of using a DNS server to convert website addresses?

• A website address is easier to remember than an IP address.

• A website address is harder to remember than an IP address.

• A website address is easier to remember than a MAC address.

• A website address is harder to remember than a MAC address.

Describe how packets are used to send data across the Internet.

• The website data is broken down into small packets/chunks of data, each packet is numbered, given the sender's and recipient's IP address, and sent separately. Packets can take different routes through the Internet based on the most efficient route. Packets are reassembled at the destination and checked for errors; lost or corrupted packets are resent.

• The website data is sent as a single large file, which is then reassembled at the destination.

• The website data is broken down into small packets, each packet is sent to the same route, and reassembled at the destination without checking for errors.

• The website data is sent in a continuous stream without breaking it into packets.

Explain the benefits of using layers in TCP/IP.

• Each layer is self-contained so can be changed without affecting other layers. Discrete layers help with interoperability between hardware manufacturers and computer systems. Developers can concentrate on one network area without worrying about how the others work.

• Each layer is dependent on the other layers, making it difficult to change one without affecting the others.

• Layers in TCP/IP do not help with interoperability between different systems.

• Developers need to understand all layers to work on any network area.

State one advantage and one disadvantage of a mesh network over a star network.

• Advantage: Mesh networks are self-healing/have no single point of failure/more resilient due to redundancy. Disadvantage: Mesh networks can be expensive to install due to redundant connections; network maintenance and administration is more complicated than with a star network.

• Advantage: Mesh networks are cheaper to install. Disadvantage: Mesh networks are less resilient due to redundancy.

• Advantage: Mesh networks have a single point of failure. Disadvantage: Mesh networks are easy to maintain.

• Advantage: Mesh networks are less resilient due to redundancy. Disadvantage: Mesh networks are cheaper to install.

Define the term 'protocol'.

• A set of rules.

• A type of hardware.

• A software application.

• A network topology.

Name two types of physical transmission media used for network cabling: _____ and _____.

Encryption is the process of _____ information to prevent unauthorized access.