Chapter 1

Question 1

How many layers in ISO OSI?

Answer 1

7

Question 2

What are the layers in ISO OSI

Answer 2

7 = application
6 = presentation
5 = session
4 = transport
3 = network
2 = data link
1 = physical

Question 3

What does OSI stand for?

Answer 3

Open Systems Interconnection

Question 4

what does ISO refer to and where is the real name derived from

Answer 4

International Standards organization and it comes from the Greek language and mean same

Question 5

What is a protocol?

Answer 5

Set of conventions (agreed-upon way of doing things

Question 6

What is the OSI model used for today?

Answer 6

It is used as a reference model

Question 7

What are the common protocols in the 7th layer?

Answer 7

HTTP SMTP and POP3

Question 8

What does POP3 stand for and what is it used for

Answer 8

Post Office Protocol version 3, used to retrieve email from a server

Question 9

Give an HTTP example to retrieve a index.htm file from www.xx.co.za

Answer 9

GET /index.htm HTTP/1.1

Question 10

What are some standards used in Layer 6?

Answer 10

XML HTML MIME

Question 11

What does layer 4 enable?

Answer 11

process-to-process communication

Question 12

what is the purpose of layer 3?

Answer 12

It performs routing functions. most commonly it just shows the next router on the path

Question 13

what is the purpose of layer 2?

Answer 13

Provide mean to transfer data between network entities and to detect/correct errors that may occur in physical layers

Question 14

What is layer 1 made up of?

Answer 14

Since it is the physical layer it is made up of copper cables and so on

Question 15

List all the bodies that issue standards:

Answer 15

ISO, IEEE, IETF, IANA,ICANN,W3C,CCITT,NIST

Question 16

What type of oriented protocols does the application layer have?

Answer 16

User-oriented protocols

Question 17

Most common architecture in this course?

Answer 17

client-server

Question 18

On what layer is FTP?

Answer 18

Layer 7

Question 19

What is the problem with client-server architecture?

Answer 19

Client always initiates communication

Question 20

What does P2P (Peer-to-Peer) enable?

Answer 20

different participants to work as equals

Question 21

by what RFC is SMTP defined by?

Answer 21

RFC 5321

Question 22

What is an alternative to POP3?

Answer 22

IMAP4 (Internet Message Access Protocol

Question 23

What is the most well known tool to see traffic on a network?

Answer 23

WireShark

Question 24

What does DNS stand for?

Answer 24

Domain name system

Question 25

What is a TLD?

Answer 25

Top level domain

Question 26

What are the types of TLD's

Answer 26

gTLD, ccTLD,sTLD

Question 27

what does gTLD stand for

Answer 27

generic TLD

Question 28

what does ccTLD stand for?

Answer 28

country code TLD

Question 29

what does sTLD stand for?

Answer 29

Sponsored TLD

Question 30

What does SCADA system do?

Answer 30

Controls industrial equipment from a single point in a facility

Question 31

What was X25 used for?

Answer 31

Routes network across international waters

Question 32

When did tim burners lee invent the www?

Answer 32

1990

Question 33

why are standards needed?

Answer 33

So that computers can communicate with each other

Question 34

what does set type=a do?

Answer 34

it is Used to specify that you want to query for the Address (A) records associated with a domain name.

Question 35

What is the difference between FQDN(fully qualified domain name) and a normal domain name

Answer 35

Normal = refer to a name within some current domain. FQDN = specifies domain starting at the TLD down to the domain name of interest

Question 36

what does set type=ns do?

Answer 36

tells nslookup that we want a pointer to a name server rather than the address associated with the domain

Question 37

what does nslookup do?

Answer 37

Show how Domain Names is translated to IP address

Question 38

What is a zone file?

Answer 38

A file that stores the Domain Info. Defines Resource records. authorative source.

Question 39

How do you determine the owner of a domain?

Answer 39

Enter whois "xx.co.za" command

Question 40

By who is IANA operated by?

Answer 40

ICANN (Internet Corporation for Assigned Names and Numbers)

Question 41

Who has authority at the root of the DNS?

Answer 41

IANA (Internet Assigned Numbers Authority)

Question 42

what does a CNAME(canonical name) do?

Answer 42

Assigns an alias to a domain name

Question 43

In the ISO each layer provides services for the layer directly ... it. Each layer uses the services provided by the layer directly ... it

Answer 43

above. below

Question 44

Is the OSI model a specific set of protocols?

Answer 44

No. it is just a reference model

Question 45

what port does ssh use

Answer 45

22

Question 46

What port does SMTP use

Answer 46

25

Question 47

What port does HTTP use

Answer 47

80

Question 48

What port does telnet use?

Answer 48

23

Question 49

What port does FTP control use?

Answer 49

21

Question 50

What port does FTP data use?

Answer 50

20

Question 51

Why is FTP still used?

Answer 51

There are many functions that can be used to make file handling easier

Question 52

What is passive connection

Answer 52

---------> actor ----------> server else -----------> actor <---------- server bottom = control connection top = data connection

Question 53

What can layer 6 do?

Answer 53

Translate.(converting) XML HTML MIE ARPA

Question 54

What does RFC stand for?

Answer 54

Request for Comments

Question 55

What is the main idea for transport layer 4?

Answer 55

Have a path between processes that participate in the convo. It can also throttle data that goes across it

Question 56

What is the purpose of layer 3?

Answer 56

to route the messages

Question 57

What does layer 2 do?

Answer 57

marks the beginning and end of a message