4.9.4 TCP/IP

Question 1

What is a protocol?

Answer 1

Set of pre-agreed rules that defines how data is transmitted over a network

Question 2

What does TCP/IP stand for?

Answer 2

Transmission control protocol / internet protocol

Question 3

What is the application layer of the TCP/IP protocol do?

Answer 3

Decides appropriate protocols depending on users choice of output.
eg. HTTP (HyperText), SMTP (Standard Mail) and FTP (File)

Question 4

What is the transport layer of the TCP/IP protocol do?

Answer 4

Splits data into packets , each packet assigned source and destination port numbers and sequence numbers (position within packets for reconstruction)
eg. TCP (Transmission control)

Question 5

What is the Network layer of the TCP/IP protocol do?

Answer 5

Encapsulate data with source and final destination IPs

Question 6

What is the Link layer of the TCP/IP protocol do?

Answer 6

Encapsulate data with source and destination MAC’s (For next router -hop- not final destination). Link header stripped at each router and new source and destination MAC’s are assigned.

Question 7

What is a MAC address?

Answer 7

Address embedded in NIC used to identify devices within a network

Question 8

What is a socket in the context of TCP/IP and routing packets?

Answer 8

Combination of an IP address and port number used for receiving and sending data over a network

Question 9

What is a socket in the context of TCP/IP and routing packets?

Answer 9

Combination of an IP address and port number used for receiving and sending data over a network

Question 10

What is a port number in the context of TCP/IP and routing packets?

Answer 10

16 bit number used to identify the process which data is sent/received by a host device. They distinguish different apps running on the same device.

Question 11

What is a packet?

Answer 11

Small section of data split into equal pieces to be transferred over a network

Question 12

What does HTTP stand for ?

Answer 12

Hyper-text transfer protocol

Question 13

How does HTTP work ?

Answer 13

Client sends an HTTP request for a webpage to server. Server receives request and sends a http response encapsulating web page to client.

Question 14

What is HTTPS ?

Answer 14

HTTP Secure

Question 15

How does HTTPS keep your data private ?

Answer 15

Encrypts it by providing a digital certificate containing encryption key. and only the authorised server possesses the corresponding key to decrypt it.

Question 16

What does FTP stand for ?

Answer 16

File transfer protocol

Question 17

What does FTP do and how is it used ?

Answer 17

Move files between two devices through a client server application like downloading / uploading software or music.

Question 18

What does POP3 stand for ?

Answer 18

Post office protocol

Question 19

What does IMAP stand for ?

Answer 19

Internet message access protocol

Question 20

What does POP3 do ?

Answer 20

Retrieves emails by downloading them onto a clients device and deletes them from the server

Question 21

What does IMAP do ?

Answer 21

Retrieves emails by creating copies on the local client device and synchronises any deletion between the server and the device (can manage btwn devices).

Question 22

What does SMTP stand for ?

Answer 22

Simple mail transfer protocol

Question 23

What does SMTP do and how does it work ?

Answer 23

Sends emails by transferring email from clients device to server then forwards it to the recipients mail server if on a different domain.

Question 24

What is SSH

Answer 24

Secure shell provides an encrypted connection for remote access to another device by encrypting messages btwn the device and server.

Question 25

What are some of SSH’s uses ?

Answer 25

. Tunnel other protocols over the internet
. Network administrators to perform software upgrades
. Network administrators to stop/start devices (Manage them)