2.1 - Introduction to IP

Question 1

In the moving truck analogy, what is the truck?

Answer 1

The truck is the Internet Protocol.

Question 2

In the moving truck analogy, what do the boxes hold?

Answer 2

Data.

Question 3

In the moving truck analogy, how is the box labeled?

Answer 3

The box is labeled with a port number, which would correspond to the “room” in the “house”, or the application on the computer/server.

Question 4

Explain the breakdown of what is contained within the ethernet payload.

Answer 4

The ethernet payload, with a ethernet header and trailer, will consist of an IP header and an IP payload. The IP payload might consist of a TCP header with a TCP payload, and the TCP payload itself can consist of different types of data.

Question 5

At what level on the OSI model do TCP and UDP operate?

Answer 5

OSI Level 4.

Question 6

What does it mean for TCP to be “connection-oriented”?

Answer 6

It means that there is a formal setup and close to the connection.

Question 7

What does it mean for TCP to be “reliable”?

Answer 7

It can resend data that was missed entirely or resend data that was sent out of order.

Question 8

What does it mean for TCP to have “flow control”?

Answer 8

The receiving device can decide the flow of information being sent.

Question 9

What does UDP stand for?

Answer 9

User Datagram Protocol

Question 10

What does TCP stand for?

Answer 10

Transmission Control Protocol

Question 11

What does it mean for UDP to be “connectionless”?

Answer 11

There is no formal open or close to the connection

Question 12

What does it mean for UDP to be “unreliable”?

Answer 12

It means that there is no receipt/acknowledgment from the receiving device that the data was received.

Question 13

Does UDP have flow control?

Answer 13

No.

Question 14

What is the most common use of UDP?

Answer 14

Real-time communication (e.g., phone calls).

Question 15

What are two connectionless protocols and what are they used for?

Answer 15

DHCP - Dynamic Host Configuration Protocol, used to automatically assign IP addresses to devices
TFTP - Trivial File Transfer Protocol

Question 16

What are two connection-oriented protocols?

Answer 16

HTTPS (Hypertext Transfer Protocol Secure), commonly used for data in web browsers and SSH (Secure Shell), used for an encrypted form of terminal communication between devices.

Question 17

What is a “non-ephemeral” port number?

Answer 17

A permanent port number, usually on a server or a service, that does not change and is not temporary. Usually ports 0 through 1,023.

Question 18

What is an “ephemeral” port number?

Answer 18

A temporary port number, usually from 1,024 through 65,535 that is determined in real-time by the client.