Network Models

Question 1

What is the 7 layer OSI model?

Answer 1

Open Systems Interconnection, model is a conceptual framework that divides network communications functions into seven layers that explains how a network works.

Question 2

What are the 7 layers of the OSI model?

PDNTSPA

Answer 2

1. Physical
2. Data Link
3. Network
4. Transport
5. Session
6. Presentation
7. Application

Question 3

What is the Physical layer of the OSI model?

Answer 3

1st layer, Cabling, network card, getting 1’s and 0’s from one machine to another.

Question 4

What is the Data Link layer of the OSI model?

Answer 4

2nd Layer, Mac Addresses / for NICs and Switches

Question 5

What is the Network layer of the OSI model?

Answer 5

3rd Layer, Logical addresses, TCP/IP and Routers, packets are created

Question 6

What is the Transport layer of the OSI model?

Answer 6

4th Layer, assembles and disassembles data 1500 bytes maximum, sequencing, segments

Question 7

What is the Session Layer of the OSI Model?

Answer 7

5th layer, makes the actual connection to the remote host or other computers, uses Port numbers

Question 8

What is the Presentation Layer of the OSI Model?

Answer 8

6th layer, makes sure that the Data gets to the application, not really important anymore.

Question 9

What is the Application Layer of the OSI Model?

Answer 9

7th Layer, API or Application Program Interface, smart application

Question 10

How is Data transferred from one device to another?

Answer 10

Frames or Packets in chunks of 1’s and 0’s

Question 11

What is the cornerstone of Networking?

Answer 11

Packetized Data

Question 12

Frames are created and destroyed in what hardware device?

Answer 12

Network Card (NIC)

Question 13

Each hexadecimal character has?

Answer 13

4 binary characters ex: ( 40-8d-5c-1c-5a-50 ) = 12x4=48 Bit address

Question 14

1st 3 - Hexadecimals ( 40-8d-5c ) are known as:

Answer 14

OEM identifier

Question 15

Last 3 - Hexadecimals ( 1c-5a-50 )

Answer 15

Unique identifier

Question 16

CRC stands for what?

Answer 16

Cyclic Redundancy Check ( verifies data is good )

Question 17

All “F’s” address ( FF-FF-FF-FF-FF-FF ) is a :

Answer 17

Broadcast domain ( sends to all machines on the network )

Question 18

Domain that know a one specific mac address is:

Answer 18

Unicast domain ( Only sends to one Single Machine )

Question 19

Logical Address

Answer 19

Is considered a Virtual Address, doesn’t physically exist

Question 20

IP addressing

Answer 20

The unique identifying number assigned to every device connected to the internet

Question 21

IP Packets never travel by themselves, they are always incapsulated by a:

Answer 21

Frame

Question 22

IP Packets never Change but:

Answer 22

Frames do

Question 23

Some Port numbers ( ex: 80-1694 ) are unique to applications:

Answer 23

80 - Internet or web page ( HTTP )
20 and 21 - are for FTP

Question 24

Port numbers can be up to:

Answer 24

0 - 65535, they direct packet traffic between the source and destination computers

Question 25

What and how many port numbers are reserved ( or well known ports )?

Answer 25

1st 1024

Question 26

Routers look at _____ not MAC addresses.

Answer 26

IP addresses

Question 27

Every router has one of these and based on the network information of the packet, where to actually send the data:

Answer 27

Routing Table

Question 28

TCP, which makes sure data gets from PC to PC completely stands for:

Answer 28

Transmission Control Protocol ( Connection oriented )

Question 29

2 big pieces of TCP are:

Answer 29

Sequencing number and Acknowledgement Number

Question 30

What protocol is connectionless, just sends data and hopes:

Answer 30

UDP ( User Datagram Protocol ) used for videos and gaming

Question 31

How does the network software know how to reassemble a file?

Answer 31

Sequencing numbers

Question 32

This hardware device Generates, receives, and destroys frames:

Answer 32

NIC network interface card

Question 33

Packets come from what layer:

Answer 33

Layer 3 or Network Layer

Question 34

Segments and sequencing take place and come from what layer:

Answer 34

Layer 4 or Transport layer

Question 35

What is & describes physical addressing, and the rules about creating and transmitting frames:

Answer 35

MAC ( Media Access Control )

Question 36

Mediums and Cablings are also known as:

Answer 36

Topologies

Question 37

MAC addresses use hexadecimal values of:

Answer 37

0-9 and A-F only

Question 38

2 types of Topologies are:

Answer 38

Physical - how a network is laid out. Logical - Explains how data is sent between them.

Question 39

What is the oldest Topology computers share the same bandwidth and utilize "Drop Downs" or one single trunk

Answer 39

Bus Topology

Question 40

IBM Token Ring - all computers are connected in a ring:

Answer 40

Ring Topology

Question 41

Computers are plugged into a hub / switch in the center of the computers

Answer 41

Star Topology

Question 42

Most popular Topology used today

Answer 42

Star-Bus / or Hybrid Topology

Question 43

Where all hosts are connected to all host at the same time and is great for Wireless networks.

Answer 43

Mesh Topology (or Mess)

Question 44

Mesh Topologies have __________ which when a cable breaks between 2 computers, it doesn't affect the connection between the other machines.

Answer 44

Fault tolerance

Question 45

large Partially Mesh networks use________ for better connectivity

Answer 45

Extenders

Question 46

What is the Electronic Circuit Flow of Frames

Answer 46

Logical Topology

Question 47

Examples of a broadcast IP address:

Answer 47

192.255.255.255 or 192.168.255.255 or 255.255.255.255