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Question 1

What is TCP

Answer 1

Transmission Control Protocol is an established session between 2 devices before communication takes place.

Question 2

What layer does IPsec operate on

Answer 2

Network Layer

Question 3

What is the Network Layer?

Answer 3

The network layer is responsible for routing from one network to another. The network does not specify how the data is passed but provides the protocols.

Question 4

Name 2 methods routers can be configured.

Answer 4

Statically: Manual entires to routing tables
Dynamically: Routing protocols such as Routing Information Protocol (RIP) and Open Shortest Path First (OSPF)

Question 5

What are the protocols responsible for the Network Layer?

Answer 5

The protocols are responsible for route selection and determining the best path in the network.

Question 6

What is Segmentation in the Transport Layer?

Answer 6

Data blocks must be broken into packets to traverse the lower layers.

Question 7

Name 2 functions of data flow control in the Transport Layer.

Answer 7

• Buffering: Data is stored temporarily and waits for the receiving device to become available.
• Windowing: Data is sent in group of segments that require one acknowledgement. Window size is defined when a session is established and one ACK every five segments.

Question 8

What does the Presentation Layer do?

Answer 8

Converts data intended for or received from the application layer into another format.

Question 9

What does the Application Layer do?

Answer 9

Takes the user’s request and data, passing them to the lower layer. This layer of service includes file and print capabilities.

Question 10

Characteristics of the physical layer (3)

Answer 10

Hardware: Type of Media used in the network
Topology: Identify what topology the network is using
Dictates the bandwidth speed over the medium

Question 11

What type of data is encapsulated in each of the layers (3)

Answer 11

Data link: Frame
Network: Packets
Transport: Segment

Question 12

What is connection-oriented protocol

Answer 12

Connection-oriented protocol is data delivery guaranteed. TCP

Question 13

What is Connectionless protocols

Answer 13

Connectionless protocols offers best-effort delivery mechanisms.

Question 14

What is MTU

Answer 14

Maximum Transmission Unit which limits the data packet size in transmission

Question 15

What does TCP provide (4)

Answer 15

• Reliability
• Flow Control Sequencing
• Error Detection
• Correction

Question 16

Explain how TCP Works/Handshake

Answer 16

1. Sends a SYN message to the Host
2. Host will open a connection for request and send back an acknowledgement message called an ACK or SYN-ACK
3. Host that originated the request sends back another acknowledgement, saying they have received the ACK message and that the session is ready to transfer

Question 17

How does TCP handle errors

Answer 17

They have mechanism that is timeout and retransmitting data.

Question 18

What is UDP

Answer 18

User Datagram Protocol is a transport protocol. UDP offers connectionless protocol.

Question 19

How many fields does TCP and UDP packet have

Answer 19

TCP has 14 fields
UDP has 4 fields

Question 20

What is ICMP

Answer 20

Internet Control Message Protocol works with the IP Layer to provide error checking and reporting

Question 21

What is Source Quench Message

Answer 21

Receiving hosts cannot handle the influx of data and will let the sender know to slow down.

Question 22

What is IPSec

Answer 22

IP Security responsible for encrypting and authentication during network Transmissions

Question 23

What are the 2 protocols in IPSec

Answer 23

Authentication Header AH
Encapsulating Security Payload ESP

Question 24

What does Authentication Header do

Answer 24

AH provides the authentication and integrity of the data packets