Chapter 2

Question 1

What does the Presentation Layer do?

Answer 1

Translates layers to a standard format and manages encryption and data compression. Includes protocols such as FTP and SSH

Question 2

What does the Session layer do?

Answer 2

Is a collection of protocols that help establish and make applications available on computers across the network.

Question 3

What does the transmission layer do, and what protocols does it use?

Answer 3

Manages transmission and verification of data being sent between hosts. Uses TCP and UDP protocols.

Question 4

What are the layers of the OSI Model?

Answer 4

Application
Presentation
Session
Transport
Network
Data Link
Physical

Question 5

What are the layers of the DoD Model?

Answer 5

Process/Application
Host to Host
Internet
Network Access

Question 6

How many bits if a MAC Address, and what notation is used to express it?

Answer 6

48 bits, hexadecimal. Usually six 8-bit groups, but could be written in three groups of 4.

Question 7

What are the two categories of MAC Addresses

Answer 7

Universally Administered Addresses (UAA)
Locally Administered Addresses (LAA)

Question 8

Describe the Universally Administered Addresses (UAA).

Answer 8

Administered and assigned by the manufacturer of the device.
IEEE assigns the first 24 bits that identify the manufacturer. (OUI Code)
Manufacturer assigns the other 24 bits for the serial number.

Question 9

Describe Locally Administered Addresses (LAA).

Answer 9

Useful for when there are duplicate MAC addresses, which is not common. Commonly used for the administrator to dynamically assign an address for virtual interfaces, such as hypervisors.

Question 10

What are the parts of an ethernet frame?
What is the number of bytes for each part of the frame?

Answer 10

Preamble (8 bytes)
Destination Address (6 bytes)
Source Address (6 bytes)
Length (2 bytes)
Data (46-1500 bytes)
Frame Check Sequence (4 bytes)