CCNP Switch FAQ: VLANs and Trunks

CCNP Switch FAQ: VLANs and Trunks

1. A VLAN is which of the following?
a. Collision domain
b. Spanning-tree domain
c. Broadcast domain
d. VTP domain

Answer: C

Figure: VLAN Functionality

2. Switches provide VLAN connectivity at which layer of the OSI model?
a. Layer 1
b. Layer 2
c. Layer 3
d. Layer 4

Answer: B

3. Which one of the following switch functions is needed to pass data between twoPCs, each connected to a different VLAN?
a. Layer 2 switch
b. Layer 3 switch
c. Trunk
d. Tunnel

Answer: B

4. Which Catalyst IOS switch command is used to assign a port to a VLAN?
a. access vlanvlan-id
b. switchport access vlanvlan-id
c. vlanvlan-id
d. set port vlanvlan-id

Answer: B

5. Which of the following is a standardized method of trunk encapsulation?
a. 802.1d
b. 802.1Q
c. 802.3z
d. 802.1a

Answer: B

6. What is the Cisco proprietary method for trunk encapsulation?
a. CDP
b. EIGRP
c. ISL
d. DSL

Answer: C

7. Which of these protocols dynamically negotiates trunking parameters?
a. PAgP
b. STP
c. CDP
d. DTP

Answer: D

8. How many different VLANs can an 802.1Q trunk support?
a. 256
b. 1024
c. 4096
d. 32,768
e. 65,536

Answer: C

9. Which of the following incorrectly describes a native VLAN?
a. Frames are untagged on an 802.1Q trunk.
b. Frames are untagged on an ISL trunk.
c. Frames can be interpreted by a nontrunking host.
d. The native VLAN can be configured for each trunking port.

Answer: B

10. If two switches each support all types of trunk encapsulation on a link between them, which one will be negotiated?
a. ISL
b. 802.1Q
c. DTP
d. VTP

Answer: A

11. Which VLANs are allowed on a trunk link by default?
a. None
b. Only the native VLAN
c. All active VLANs
d. Only negotiated VLANs

Answer: C

12. Which command configures a switch port to form a trunk without using negotiation?
a. switchport mode trunk
b. switchport mode trunk nonegotiate
c. switchport mode dynamic auto
d. switchport mode dynamic desirable

Answer: A

13. Two hosts are connected to switch interfaces Gigabit Ethernet 1/0/1 and 1/0/33, but they cannot communicate with each other. Their IP addresses are in the 192.168.10.0/24 subnet, which is carried over VLAN 10. Theshow vlan id 10 command generates the following output:

The hosts are known to be up and connected. Which of the following reasons might be causing the problem? (Choose all that apply.)
a. The two hosts are assigned to VLAN 1.
b. The two hosts are assigned to different VLANs.
c. Interface Gigabit Ethernet 1/0/33 is a VLAN trunk.
d. The two hosts are using unregistered MAC addresses.

Answer: B, C. Interface Gig1/0/33 is not listed as a member of VLAN 10, so it could be configured for a different VLAN. The interface could also be configured as a trunk carrying one or more VLANs. In that case, it would not be listed as a member of VLAN 10 only.

14. A trunk link between two switches did not come up as expected. The configuration
on Switch A is as follows:

The interface configuration on Switch B is as follows:

Assuming the interfaces began with a default configuration before the commands were applied, which one of the following reasons is probably causing the problem?
a. The two switches do not have matchingswitchport trunk allowed vlan commands.
b. Neither switch has a native VLAN configured.
c. Both switches are configured in the dynamic auto mode.
d. Switch B is configured to use access VLAN 5.

Answer: C. Because the interfaces begin with their default configurations, each one uses native VLAN 1. Even though the interfaces are not configured with a consistent list of allowed VLANs, that will not prevent the trunk link from being negotiated. The real reason the trunk is not working is that both switches are configured with dynamic auto mode, causing neither switch to actively negotiate a trunk. Instead, each switch is waiting for the other one to ask for a trunk link.

15. What command configures an IP phone to use VLAN 9 for voice traffic?
a. switchport voice vlan 9
b. switchport voice-vlan 9
c. switchport voice 9
d. switchport voip 9

Answer: A

16. What is the default voice VLAN condition for a switch port?
a. switchport voice vlan 1
b. switchport voice vlan dot1p
c. switchport voice vlan untagged
d. switchport voice vlan none

Answer: D

17. If the following interface configuration commands have been used, what VLAN numbers will the voice and PC data be carried over, respectively?

a. VLAN 50, VLAN 20
b. VLAN 50, VLAN 1
c. VLAN 1, VLAN 50
d. VLAN 20, VLAN 50
e. VLAN 50, VLAN 10

Answer: E

18. A Cisco lightweight wireless access point is connected to switch interface Gigabit Ethernet 1/0/20. Which one of the following commands enables you to configure the interface on the switch?
a. switchport access vlan 50
switchport mode access
b. switchport trunk allowed vlan 1-100
switchport mode trunk
c. switchport ap vlan 50
d. no switchport mode dynamic autonomou

Answer: A

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