CCNA 1 Chapter 5 V5.0 Answers

1.

A store-and-forward switch always stores the entire frame before forwarding, and checks its CRC and frame length. A cut-through switch can forward frames before receiving the destination address field, thus presenting less latency than a store-and-forward switch. Because the frame can begin to be forwarded before it is completely received, the switch may transmit a corrupt or runt frame. All forwarding methods require a Layer 2 switch to forward broadcast frames.

 

2. Open the PT Activity. Perform the tasks in the activity instruction and then answer the question.

What destination address will PC1 include in the destination address field of the Ethernet frame that it sends to PC2?

192.168.0.17

192.168.0.34

0030.a3e5.0401

00e0.b0be.8014

0007.ec35.a5c6

 

3. A Layer 2 switch is used to switch incoming frames from a 1000BASE-T port to a port connected to a 100Base-T network. Which method of memory buffering would work best for this task?

port-based buffering

level 1 cache buffering

shared memory buffering

fixed configuration buffering

 

4.

Refer to the exhibit. PC1 issues an ARP request because it needs to send a packet to PC2. In this scenario, what will happen next?​

PC2 will send an ARP reply with its MAC address.

RT1 will send an ARP reply with its Fa0/0 MAC address.​

RT1 will send an ARP reply with the PC2 MAC address.​

SW1 will send an ARP reply with the PC2 MAC address.​

SW1 will send an ARP reply with its Fa0/1 MAC address.​

 

5. Which two statements describe features or functions of the logical link control sublayer in Ethernet standards? (Choose two.)

Logical link control is implemented in software.

Logical link control is specified in the IEEE 802.3 standard.

The LLC sublayer interacts directly with the NIC driver software.

The data link layer uses LLC to communicate with the upper layers of the protocol suite.

The LLC sublayer is responsible for the placement and retrieval of frames on and off the media.

 

6. A network administrator issues the following commands on a Layer 3 switch:

DLS1(config)# interface f0/3

DLS1(config-if)# no switchport

DLS1(config-if)# ip address 172.16.0.1 255.255.255.0

DLS1(config-if)# no shutdown

DLS1(config-if)# end

What is the administrator configuring?

a routed port

a switched virtual interface

a Cisco Express Forwarding instance

a trunk interface

 

7. What are two potential network problems that can result from ARP operation? (Choose two.)

Manually configuring static ARP associations could facilitate ARP poisoning or MAC address spoofing.

On large networks with low bandwidth, multiple ARP broadcasts could cause data communication delays.

Network attackers could manipulate MAC address and IP address mappings in ARP messages with the intent of intercepting network traffic.

Large numbers of ARP request broadcasts could cause the host MAC address table to overflow and prevent the host from communicating on the network.

Multiple ARP replies result in the switch MAC address table containing entries that match the MAC addresses of hosts that are connected to the relevant switch port.

 

8. A host is trying to send a packet to a device on a remote LAN segment, but there are currently no mappings in its ARP cache. How will the device obtain a destination MAC address?

It will send an ARP request for the MAC address of the destination device.

It will send an ARP request for the MAC address of the default gateway.

It will send the frame and use its own MAC address as the destination.

It will send the frame with a broadcast MAC address.

It will send a request to the DNS server for the destination MAC address.

 

9.

Refer to the exhibit. The exhibit shows a small switched network and the contents of the MAC address table of the switch. PC1 has sent a frame addressed to PC3. What will the switch do with the frame?

The switch will discard the frame.

The switch will forward the frame only to port 2.

The switch will forward the frame to all ports except port 4.

The switch will forward the frame to all ports.

The switch will forward the frame only to ports 1 and 3.

 

10. What are two features of ARP? (Choose two.)

If a host is ready to send a packet to a local destination device and it has the IP address but not the MAC address of the destination, it generates an ARP broadcast.

An ARP request is sent to all devices on the Ethernet LAN and contains the IP address of the destination host and its multicast MAC address.

When a host is encapsulating a packet into a frame, it refers to the MAC address table to determine the mapping of IP addresses to MAC addresses.

If no device responds to the ARP request, then the originating node will broadcast the data packet to all devices on the network segment.

If a device receiving an ARP request has the destination IPv4 address, it responds with an ARP reply.

 

11. Which statement is true about MAC addresses?

MAC addresses are implemented by software.

A NIC only needs a MAC address if connected to a WAN.

The first three bytes are used by the vendor assigned OUI.

The ISO is responsible for MAC addresses regulations.

 

12. A network administrator is connecting two modern switches using a straight-through cable. The switches are new and have never been configured. Which three statements are correct about the final result of the connection? (Choose three.)

The link between the switches will work at the fastest speed that is supported by both switches.

The link between switches will work as full-duplex.

If both switches support different speeds, they will each work at their own fastest speed.

The auto-MDIX feature will configure the interfaces eliminating the need for a crossover cable.

The connection will not be possible unless the administrator changes the cable to a crossover cable.

The duplex capability has to be manually configured because it cannot be negotiated.

 

13. When would a switch record multiple entries for a single switch port in its MAC address table?

when a router is connected to the switch port

when multiple ARP broadcasts have been forwarded

when another switch is connected to the switch port

when the switch is configured for Layer 3 switching

 

14. Fill in the blank.

The binary number 0000 1010 can be expressed as..0A..in hexadecimal.

 

15. How does adding an Ethernet line card affect the form factor of a switch?

by increasing the back plane switching speed

by expanding the port density

by making the switch stackable

by expanding the NVRAM capacity

 

16. What is the purpose of the preamble in an Ethernet frame?

is used as a padding for data

is used for timing synchronization

is used to identify the source address

is used to identify the destination address

 

17. Which two statements are correct about MAC and IP addresses during data transmission if NAT is not involved? (Choose two.)

A packet that has crossed four routers has changed the destination IP address four times.

Destination MAC addresses will never change in a frame that goes across seven routers.

Destination and source MAC addresses have local significance and change every time a frame goes from one LAN to another.

Destination IP addresses in a packet header remain constant along the entire path to a target host.

Every time a frame is encapsulated with a new destination MAC address, a new destination IP address is needed.

 

18. Which two statements describe a fixed configuration Ethernet switch? (Choose two.)

The switch cannot be configured with multiple VLANs.

An SVI cannot be configured on the switch.

A fixed configuration switch may be stackable.

The number of ports on the switch cannot be increased.

The port density of the switch is determined by the Cisco IOS.

 

19. What is a characteristic of a contention-based access method?

It processes more overhead than the controlled access methods do.

It has mechanisms to track the turns to access the media.

It is a nondeterministic method.

It scales very well under heavy media use.

 

20. What is the Layer 2 multicast MAC address that corresponds to the Layer 3 IPv4 multicast address 224.139.34.56?

00-00-00-0B-22-38

01-00-5E-0B-22-38

01-5E-00-0B-22-38

FE-80-00-0B-22-38

FF-FF-FF-0B-22-38

 

21. What statement illustrates a drawback of the CSMA/CD access method?

Deterministic media access protocols slow network performance.

It is more complex than non-deterministic protocols.

Collisions can decrease network performance.

CSMA/CD LAN technologies are only available at slower speeds than other LAN technologies.

 

22. Which address or combination of addresses does a Layer 3 switch use to make forwarding decisions?

IP address only

port address only

MAC address only

MAC and port addresses

MAC and IP addresses

 

23.