Network Models

Question 1

What are protocols?

Answer 1

rules, regulations, standards and procedures that allow hardware and software developers to make devices and applications that function properly at a particular layer

Question 2

OSI Layers?

Answer 2

Layer 7 Application
Layer 6 Presentation
Layer 5 Session
Layer 4 Transport
Layer 3 Network
Layer 2 Data Link
Layer 1 Physical
( All People Seem To Need Data Processing )

Question 3

What is UTP?

Answer 3

Unshieled Twisted Pair

Question 4

What is Layer 1?

Answer 4

Physical

• defines method of moving data between computers
• central box, copper cabling, fiber optics, radio waves

Question 5

What is a NIC?

Answer 5

Network Interface Card

- serves as the interace between PC and network

Question 6

What is a MAC address?

Answer 6

Media Access Control Address

• 48 bit unique identifier
• also known as physical address

Question 7

What is the OUI?

Answer 7

Organizationally Unique Identifer

• first six digits of a MAC address
• identifies manufacturer

Question 8

What is the last portion of the MAC Address?

Answer 8

Device ID

Question 9

See the mac address in Windows?

Answer 9

ipconfig /all (called physical address)

Question 10

See the mac address in Mac?

Answer 10

ifconfig (called ?)

Question 11

See the mac address in Linux?

Answer 11

ip a (called link/ether)

Question 12

Other names for a MAC address?

Answer 12

MAC-48

EUI-48 (Extended Unique Identifier)

Question 13

Unit of data at each layer is called?

Answer 13

Protocol Data Unit (PDU)

Question 14

Can NICs on the same network use different types of frames?

Answer 14

No

Question 15

What are the parts of a frame?

Answer 15

Header:
- receiving MAC
- sending MAC
Payload:
- Type field (indicates whats encapsulated in the frame)
Trailer:
- FCS (Frame Check Sequence)

Question 16

What is the FCS?

Answer 16

Frame Check Sequence

• Uses a cyclic redundancy check (CRC) that the receiving NIC uses to determine if the data arrived intact
• 4 bytes long
• if CRC is wrong, frame is dropped

Question 17

Size of a frame?

Answer 17

1500 bytes

Question 18

Layer 2 Broadcast Address

Answer 18

FF-FF-FF-FF-FF-FF

Question 19

A frame addressed specifically to another devices MAC address?

Answer 19

unicast frame

Question 20

Layer 2?

Answer 20

Data Link Layer

- any device that deals with a MAC address

Question 21

What is LLC?

Answer 21

Logical Link Control

- first job of the NIC, talks to the OS via device drivers

Question 22

What is MAC?

not MAC Address

Answer 22

Media Access Control

- second job of the NIC that creates and addresses frames

Question 23

What is logical addressing?

Answer 23

IP addressing

needs a network protocol

Question 24

What does TCP/IP stand for?

Answer 24

Transmission Control Protocol/Internet Protocol

Question 25

Layer 3?

Answer 25

Network Layer

- creates and addresses packets to go to another network

Question 26

What is the PDU for layer 3?

Answer 26

Packet

Question 27

Where is the MAC address stored?

Answer 27

Burned into chip on the NIC

Question 28

Parts of an IP Packet?

Answer 28

• Destination IP
• Source IP
• Data
• enclosed in a frame

Question 29

Layer 4?

Answer 29

Transport Layer

• segmentation (chops up data into chunks that will fit into packets) on sending NIC
• reassembly (reassembles data on receiving NIC)
• chunks are called segments (TCP) or datagrams (UDP)
• initializes requests for packets that weren’t recieved in good order

Question 30

Layer 5?

Answer 30

Session Layer

• accepts, opens and closes all sessions
• connects applications to applications
• keeps track of all sessions

Question 31

Layer 6?

Answer 31

Presentation Layer

- translates data from lower layers into a format usable by the application layer, and vice versa

Question 32

Layer 7?

Answer 32

Application Layer

- the code built into application that make them network-aware

Question 33

API?

Answer 33

Application Programming Interface

- a way for programmers to enhance or extend an applications capabilities

Question 34

Preparing to send out and receive data on a network?

Answer 34

Encapsulation & de-encapsulation

Question 35

View TCP connections in Windows?

Answer 35

netstat -n

Question 36

Encapsulation at Layer 2

Answer 36

Frame

Question 37

Encapsulation at Layer 3

Answer 37

IP Packet

Question 38

Encapsulation at Layer 4?

Answer 38

TCP Segment / UDP Datagram

Question 39

Encapsulation at Layer 7?

Answer 39

Data (or payload)