Networking Devices: Checkpoint Exam 4-6

Question 1

What are the six parts of the ethernet frame fields?

Answer 1

Preamble and SFD,
Destination MAC Address,
Source MAC Address,
Type / Length,
Data, &
Frame Check Sequence

Question 2

Which part of an Ethernet Frame describes the higher-layer protocol that is encapsulated?

Answer 2

EtherType

Question 3

What are the two sub layers of the data link layer?

Answer 3

Logical Link Control (LLC) and the Media Access Control (MAC)

Question 4

LLC Sublayer

Answer 4

Communicates between the networking software at the upper layers and the device hardware at the lower layers.

Question 5

MAC Sublayer

Answer 5

Implemented in hardware and is responsible for data encapsulation and media access control by checking for errors in received bits. It provides data link layer addressing and is integrated with various physical layer technologies.

Question 6

What is a function of the MAC sublayer?

Answer 6

Controls access to the media, checks for errors in received bits, & uses CSMA/CD or CSMA/CA to support Ethernet technology

Question 7

Broadcast MAC Address

Answer 7

FF-FF-FF-FF-FF-FF, flooded out all Ethernet switch ports except the incoming port, and not forwarded by a router

Question 8

Multicast MAC Address

Answer 8

01-00-5E = IPv4 or 33-33 = IPv6, flooded out all Ethernet switch ports except the incoming port (with config exeptions), and not forwarded by a router (with config exeptions

Question 9

What is encapsulated into the data field of an Ethernet frame?

Answer 9

The Layer 3 PDU

Question 10

What is the length restriction of the data field in an Ethernet frame?

Answer 10

between 46 to 1500 bytes

Question 11

Which Ethernet sublayer is used to control network access using CSMA/CD?

Answer 11

MAC

Question 12

Which three fields are found in an 802.3 Ethernet frame?

Answer 12

source physical address,
destination physical address, and
frame check sequence

Question 13

What are the network layer protocols four basic operations:

Answer 13

Addressing end devices,
Encapsulation,
Routing, and
De-encapsulation

Question 14

Which OSI layer is responsible for taking an IP packet and preparing it for transmission over the communications medium?

Answer 14

data link layer receives IP packets from the network layer and encapsulates them for transmission over the medium.

Question 15

What are the characteristics of IP:

Answer 15

Connectionless = no connection before,
Best Effort = inherently unreliable, &
Media Independent = i.e., copper, fiber-optic, or wireless

Question 16

What are all the IPv4 headers?

Answer 16

Version,
Differentiated Services,
Time to Live,
Protocol,
Header Checksum,
Source IPv4 Address, and
Destination IPv4 Address

Question 17

What are the three major issues of IPv4?

Answer 17

Depletion, No end-to-end connectivity, and network complexity

Question 18

What are the three improvments of IPv6?

Answer 18

Increased address space, Improved packet handling, and Eliminates the need for NAT

Question 19

What are all the IPv6 headers?

Answer 19

Version,
Traffic Class,
Flow Label,
Payload Length,
Next Header,
Hop Limit,
Source IPv6 Address, and
Destination IPv6 Address

Question 20

Which two options are improvements provided by IPv6 as compared to IPv4?

Answer 20

Uses a simpler header to provide improved packet handling and increased the IP address space

Question 21

Which is true of the IPv6 header?

it consists of 20 octets.
it consists of 40 octets.
it contains 8 header fields.
it contains 12 header fields.

Answer 21

it consists of 40 octets.
&
it contains 8 header fields.

Explanation: The IPv6 header is a fixed length of 40 octets and contains 8 header fields.

Question 22

Which statement accurately describes a characteristic of IPv4?

Answer 22

IPv4 has a 32-bit address space

Question 23

Which characteristic of the network layer in the OSI model allows carrying packets for multiple types of communications among many hosts?

Answer 23

The ability to operate without regard to the data that is carried in each packet.

Explanation: The function of the network layer protocols specifies the packet structure and processing used to carry the data from one host to another host. The actual communication data is encapsulated in the network layer PDU.

Question 24

Which statement describes a characteristic of the network layer in the OSI model?

Answer 24

Its protocols specify the packet structure and processing used to carry the data from one host to another

Question 25

Which layer of the OSI model is responsible for the logical addressing of packets?

Answer 25

The network layer is the layer that consists of packets containing logical (IP) addressing.

Question 26

What is the order of encapsulation for the protocol data units passing from the user application down the stack?

Answer 26

data,
segments,
packets,
frames,
& bits

Question 27

What information is added during encapsulation at OSI Layer 3?

Answer 27

source and destination IP address

Question 28

How does the network layer use the MTU value?

Answer 28

The MTU is passed to the network layer by the data link layer

Question 29

Host-A has the IPv4 address and subnet mask 172.16.4.100 255.255.0.0. What is the network address of Host-A?

Answer 29

172.16.0.0

Question 30

“Which statement describes IPv4 addressing?

Routers use the full 32-bit IP address to determine the location of each individual host.

The network portion of a destination IP address is obtained by performing an AND operation between a host IP address and a subnet mask.

An IPv4 address contains two parts: a network portion and a subnet portion.

Two hosts with the same subnet mask are in the same network.”

Answer 30

The network portion of a destination IP address is obtained by performing an AND operation between a host IP address and a subnet mask.

Explanation: An IPv4 address consists of two parts: the network portion and the host portion. Routers just need to know the network portion of each IP address to forward the packet to its destination. When a router needs to identify the network portion of an IPv4 address, an AND operation is performed between the IP address and the subnet mask. The subnet mask identifies the network portion of the host IP address, not the network IP address itself, and that is why two hosts with the same subnet mask are not necessarily in the same network.

Question 31

How many octets exist in an IPv4 address?

Answer 31

4

Explanation: Each octet holds 8 bits and an IPv4 address contains 32 bits. Therefore, an IPv4 address contains four octets.

Question 32

Which full range of decimal values are valid in one octet of an IPv4 address?

Answer 32

0 through 255

Explanation: An octet can contain 8 bits. Each bit can be a 1 or a 0 because the binary system is used. To determine the number of values that can be represented by a specific number of bits, use the formula 2x where the x represents a specific number of bits. For 8 bits, 28 = 256. The numbers 0 through 255 are the valid values. Another way of looking at it is that the lowest value would be 8 0’s or 00000000 (decimal 0). The highest value is 8 1’s or 11111111 (decimal 255).

Question 33

What is the prefix length notation for the subnet mask 255.255.255.224?

Answer 33

/27

Explanation: The binary format for 255.255.255.224 is 11111111.11111111.11111111.11100000. The prefix length is the number of consecutive 1s in the subnet mask. Therefore, the prefix length is /27.

Question 34

What do devices on the same IPv4 subnet have in common?

Answer 34

“They all use the same default gateway.

Explanation: Devices on the same subnet will share the same network number, subnet mask, and default gateway. The default gateway is the IPv4 address of the Layer 3 device that allows the devices on the same subnet to communicate with other networks.
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