New CCNA – VLAN Questions

Note: If you are not sure about Virtual Local Area Network (VLAN), please read our Virtual Local Area Network VLAN Tutorial.

Question 1

What are three benefits of implementing VLANs? (Choose three)

A. A more efficient use of bandwidth can be achieved allowing many physical groups to use the same network infrastructure
B. Broadcast storms can be mitigated by decreasing the number of broadcast domains,thus increasing their size.
C. A higher level of network security can be reached by separating sensitive data traffic from other network traffic.
D. Port-based vlans increase switch-port use efficient,thanks to 802.1Q trunks
E. A more efficient use of bandwidth can be achieved allowing many logical networks to use the same network infrastructure.
F. Broadcast storms can be mitigated by increasing the number of broadcast domains,thus reducing their size.
G. VLANs make it easier for IT staff to configure new logical groups,because the vlans all belong to the same broadcast domain.

 

Answer: C E F

Question 2

VLAN 3 is not yet configured on your switch. What happens if you set the switchport access vlan 3 command interface configuration mode?

A. The command is accepted and the respective VLAN is added to vlan.dat.
B. The command is rejected.
C. The command is accepted and you must configure the VLAN manually.
D. The port turns amber.

 

Answer: A

Explanation

Even VLAN 3 is not yet configured on the switch, we can set the switchport access vlan 3 command without no problem and it also displays when we type the “show running-config” command.

Question 3

What are three advantages of VLANs? (Choose three)

A. VLANs establish broadcast domains in switched networks.
B. VLANs utilize packet filtering to enhance network security.
C. VLANs provide a method of conserving IP addresses in large networks.
D. VLANs provide a low-latency internetworking alternative to routed networks.
E. VLANs allow access to network services based on department, not physical location.
F. VLANs can greatly simplify adding, moving, or changing hosts on the network.

 

Answer: A E F

Question 4

On corporate network, hosts on the same VLAN can communicate with each other, but they are unable to communicate with hosts on different VLANs. What is needed to allow communication between the VLANs?

A. a router with subinterfaces configured on the physical interface that is connected to the switch
B. a router with an IP address on the physical interface connected to the switch
C. a switch with an access link that is configured between the switches
D. a switch with a trunk link that is configured between the switches

 

Answer: A

Question 5

Cisco Catalyst switches CAT1 and CAT2 have a connection between them using ports Fa0/13. An 802.1Q trunk is configured between the two switches. On CAT1, VLAN 10 is chosen as native, but on CAT2 the native VLAN is not specified. What will happen in this scenario?

A. 802.1Q giants frames could saturate the link.
B. VLAN 10 on CAT1 and VLAN 1 on CAT2 will send untagged frames.
C. A native VLAN mismatch error message will appear.
D. VLAN 10 on CAT1 and VLAN 1 on CAT2 will send tagged frames.

 

Answer: C

Explanation

A “native VLAN mismatch” error will appear by CDP if there is a native VLAN mismatch on an 802.1Q link. “VLAN mismatch” can cause traffic from one vlan to leak into another vlan.

Question 6

Which of the following are benefits of VLANs? (Choose three)

A. They increase the size of collision domains.
B. They allow logical grouping of users by function.
C. They can enhance network security.
D. They increase the size of broadcast domains while decreasing the number of collision domains.
E. They increase the number of broadcast domains while decreasing the size of the broadcast domains.
F. They simplify switch administration.

 

Answer: B C E

Explanation

When using VLAN the number and size of collision domains remain the same -> A is not correct.

VLANs allow to group users by function, not by location or geography -> B is correct.

VLANs help minimize the incorrect configuration of VLANs so it enhances the security of the network -> C is correct.

VLAN increases the size of broadcast domains but does not decrease the number of collision domains -> D is not correct.

VLANs increase the number of broadcast domains while decreasing the size of the broadcast domains which increase the utilization of the links. It is also a big advantage of VLAN -> E is correct.

VLANs are useful but they are more complex and need more administration -> F is not correct.

Question 7

A frame from VLAN1 of switch S1 is sent to switch S2 where the frame received on VLAN2. What causes this behavior?

A. trunk mode mismatches
B. vlans that do not correspond to a unique IP subnet
C. native vlan mismatches
D. allowing only vlan 2 on the destination.

 

Answer: C

Explanation

For 802.1q encapsulation, the native VLAN must matched at both side; otherwise the link will not work. In this case the native VLAN of S1 is 1 while the native VLAN of S2 is 2.

Question 8

Which statement about vlan operation on Cisco Catalyst switches is true?

A. when a packet is received from an 802.1Q trunk, the vlan id can be determined from the source MAC address table.
B. unknown unicast frames are retransmitted only to the ports that belong to the same vlan.
C. ports between switches should be configured in access mode so that vlans can span across the ports.
D. broadcast and multicast frames are retransmitted to ports that are configured on different vlan.

 

Answer: B

Explanation

Answer A is not correct because when a packet is received from an 802.1Q trunk, it always carries VLAN ID information in the VLAN tag portion so the switch does not need to look up its source MAC address table to determine the VLAN ID of that packet.

Question 9

Which two benefits are provided by creating VLANs? (Choose two)
A. added security
B. dedicated bandwidth
C. provides segmentation
D. allows switches to route traffic between subinterfaces
E. contains collisions

 

Answer: A C

Question 10

Assuming the default switch configuration which vlan range can be added modified and removed on a Cisco switch?

A. 2 through 1001
B. 1 through 1001
C. 1 through 1002
D. 2 through 1005

 

Answer: A

Explanation

VLAN 1 is the default VLAN on Cisco switch. It always exists and can not be added, modified or removed.

VLANs 1002-1005 are default VLANs for FDDI & Token Ring and they can’t be deleted or used for Ethernet.