Networking and internetworking

Question 1

MAC

Answer 1

• A unique identifier assigned to network interfaces such as NIC
• A 48 bit hardware address that has a flat structure compromising of a unique manufacture ID and unique serial number for the device

Question 2

IP

Answer 2

• This address can be used by routers to make decisions on which network packets are to be sent to next
• A 32 bit address that has a logical structure compromising of a network ID and a Host ID.

Question 3

Switch

Answer 3

-

Question 4

Client

Answer 4

-

Question 5

Router

Answer 5

• A device that can direct data packets around a network in the most efficient way.

Question 6

LAN

Answer 6

• Networking equipment in this network is usually owned and maintained by the organisation
• A network that is connected in one building or one site.

Question 7

Server

Answer 7

• A software process that processes and responds to the request from a client process.
• A software process that initiates a request from a server.

Question 8

WAN

Answer 8

• A network that is connected over a large geographical area

- Networking equipment and cables are usually not owned by the organisation but leased from large Telecom businesses

Question 9

Gateway

Answer 9

-

Question 10

What is mean by the internet?

Answer 10

A global network of linked computers and routers using unique IP addresses and TCP/ IP protocol.

Question 11

People occasionally think that the World Wide Web is the same as the internet. What are the differences between the two?

Answer 11

WWW: A system of interlinked hypertext documents accessed via the internet
Internet: cabling

Question 12

A computer has an IP address of 140.234.1.25

What is an IP address and why is it used?

Answer 12

A unique address that identifies a device on a network 32 bits e.g. 192.168.168.5
Routers make decisions where packets are going to be directed to based on the IP address

Question 13

Explain in more detail how an IP address is structured

Answer 13

A 32 bit address that has a logical structure compromising of network ID and a host ID.

Question 14

Explain what is meant by a datagram. Describe how datagram is made up and how it is used.

Answer 14

• Group of bits containing source/destination address error control bits and data payload.
• Consists of data package, data payload
• Contains header and footer
• Data payload is encapsulated with information as it goes through the TCP/ IP stock

Question 15

Routers are used in computer networks. Explain what is meant by a router ad describe the function of a router in a computer network.

Answer 15

Router: device that connects networks that use the same protocol
- directs data packets through the network based on their IP address
They use routing tables that list all the networks IP addresses of networks the router is connected to therefore, router can make decisions; look up/ find certain IP addresses

Question 16

Explain why protocols are so important in communication systems

Answer 16

When data is split up and reassembled it must be in a way that is universally agreed. All devices are programmed with a set of rules to follow so manufacturers can make compatible devices.

Question 17

Why are server ports numbers well-known and registered

Answer 17

When programmers make applications they need to know what ports to communicate to the network application.

Question 18

Name the five layers o the TCP/IP protocol stack and explain the role of each layer

Answer 18

1. Application layer (HTTP) - identifies application used for this communication.
2. Transport layer (does a lot) - splits memory into packets
   
   • Adds port number: 80
   • sequence numbers
   • error check line
   • check digit
3. Network layer: IP - sender - receiver
   
   • routers will inspect IP
4. Data link layer: physical interaction with medium (cable)
   
   • MAC address is added to packet from NIC
5. Physical layer - coper cable

Question 19

In the context of client-server model, what is

• a server?
• a client?

Answer 19

• A server: system that responds to requests from clients; processes the request and sends the result back
• A client: software that initiates a request of a service from a server

Question 20

What is the difference between sockets and ports?

Answer 20

• Socket is a combination of host IP address and a port number. It forms a bidirectional communication path between the end processes or applications e.g. 192.168.168.2:1045
• Port is an address for a software process e.g. 80

Question 21

What is the difference between client and server ports?

Answer 21

-