1. Internetworking

Question 1

What does an Internetwork consist of?

Answer 1

• Two or more devices
• Connected via a router
• Logical network addressing scheme (IPV4/6)

Question 2

What can a hub more accurately be defined as?

Answer 2

A multi-port repeater.

Question 3

How does a multi-port repeater work?

Answer 3

1. Recieves a digital signal.
2. Amplifies/regenerates the digital signal.
3. Broadcasts out of all other ports.
4. Does not inspect the signal.

Question 4

Why is network segmentation employed?

Answer 4

Network Segmentation reduces congestion within the network.

Question 5

What do Cisco refer to as microsegmentation?

Answer 5

Microsegmentation is when every host is in a switch port.

Question 6

How does a switch forward a broadcast?

Answer 6

Switches put out broadcast messages on every port by default.

Question 7

What is a broadcast domain?

Answer 7

A broadcast domain is a subnet/VLAN in which if a host sends a broadcast message, all other hosts on the same subnet/VLAN will receive it.

Question 8

How does a router forward a broadcast?

Answer 8

A router does not forward broadcasts by default.

Question 9

What is a collision domain?

Answer 9

A collision domain is a network segment connected by a shared medium or through repeaters where data packets may collide with one another while being sent.

Question 10

How are the number of collision domains in a network increased?

Answer 10

Collision domains are increase through the segmentation of a network using switches.

Question 11

How are the number of broadcast domains increased within an internetwork?

Answer 11

Through the introduction of a router and additional subnets/VLANs.

Question 12

What is the connection of two or more LANs reffered to as?

Answer 12

An internetwork.

Question 13

What is the purpose of a Wireless Access Point?

Answer 13

A Wireless Access Point allows for computers to gain wireless access to wired networks

Question 14

What is the physical function of a wireless access point?

Answer 14

A Wireless Access Point acts as a modulator/demodulator, receiving digital data and transmitting analogue data (and vice versa).

Question 15

What does Duplex mean?

Answer 15

• The term ‘duplex’ signifies the ability for two points or devices to communicate with each other.
• In a duplex communication system, both points (devices) can transmit and receive information.

Question 16

What is the difference between Full-Duplex and Half-Duplex?

Answer 16

• Full-duplex communication between two components means that both can transmit and receive information between each other simultaneously.
• In half-duplex systems, the transmission and reception of information must happen alternately. While one point is transmitting, the other must only receive.

Question 17

How do Wireless Access Points operate?

Answer 17

• Wireless Access Points run at Half-Duplex.
• Using Time Division Duplexing (TDD) and splitting the time divisions very finely, Full-Duplex is emulated.
• This stops self-interference.

Question 18

What are VOIP Phones?

Answer 18

Voice Over Internet Protocol (VOIP) Phones.

Question 19

What will be increased if a Wireless Access Point is connected to a switch?

Answer 19

This will expand the collision domain.

Question 20

What is a Flat network?

Answer 20

A flat network is a large switched network which has a single large broadcast domain.

Question 21

What is the Cisco Hierarchical Model?

Answer 21

Question 22

What is a Virtual Local Area Network (VLAN) used for?

Answer 22

A VLAN is used to segment a layer 2 switched network into multiple different broadcast domains.

Question 23

What is necessary for inter-VLAN routing (IVR)?

Answer 23

A layer 3 switch or router is required for inter-VLAN routing.

Question 24

What are the layers of the OSI 7 layer model and which protocols and services correspond to these layers?

Answer 24

Question 25

What does each layer of the OSI model do?

Answer 25

Question 26

What was the OSI model created for?

Answer 26

The OSI model was created in order to enable different networks to communicate reliably accross disparate systems.

Question 27

What do the top 3 layers of the OSI model define?

Answer 27

* The top three layers of the OSI model define how the applications within the end stations communicate with each other and the users. * These layers do not contain information about networking / network addresses.

Question 28

What do the bottom 4 layers of the OSI model define?

Answer 28

The bottom 4 layers of the OSI model define: * How data is transmitted end to end. * How it is transferred through physical mediums. * How to rebuild a data stream from a transmitting host to a destination hosts' application.

Question 29

At which layer do users interact with the computer?

Answer 29

The application layer.

Question 30

What is the purpose of the presentation layer?

Answer 30

* To present data to the user. * To handle processing such as encryption.

Question 31

What is the purpose of the session layer?

Answer 31

To keep different applications' data separate.

Question 32

What does the transport layer provide?

Answer 32

The transport layer provides: * Reliable / Unreliable delivery. * Error correction before retransmit. * The segmentation and reassmbly of data in a data stream. * The reception of all data from higher layers and the combination of it into a single concise data stream. * The establishment of a logical connection between the sending host and the destination host on the network.

Question 33

What does the network layer provide?

Answer 33

The network layer provides logical addressing which routers use for path determination.

Question 34

What does the data link layer provide?

Answer 34

* The combination of packets into bytes. The subsequent comination of bytes into frames. * Access to media using MAC address. * Error detection (as opposed to correction).

Question 35

What does the physical layer provide?

Answer 35

* The movement of bits between devices. * The specification of voltage, wire speed and pin-out of cables.

Question 36

What is TCP?

Answer 36

Transmission Control Protocol (TCP) is a connection oriented protocol.

Question 37

What is UDP?

Answer 37

User Datagram Protocol (UDP) is a connectionless layer protocol.

Question 38

What steps are required for relaible communication?

Answer 38

1. A connection oriented 3-way handshake with a peer device (also known as a call setup) 2. Transfer of data 3. Termination of connection (which ends the virtual circuit).