Question 1Which feature is automatically enabled when a voice VLAN is configured, but not automatically disabled when a voice VLAN is removed?
A. portfast
B. port-security
C. spanning tree
D. storm control
Answer: A
Explanation
The Port Fast feature is automatically enabled when voice VLAN is configured. When you disable voice VLAN, the Port Fast feature is not automatically disabled.
Question 2In which portion of the frame is the 802.1q header found?
A. within the Ethernet header
B. within the Ethernet payload
C. within the Ethernet FCS
D. within the Ethernet source MAC address
Answer: A
Explanation
802.1Q VLAN frames are distinguished from ordinary Ethernet frames by the insertion of a 4-byte VLAN tag into the Ethernet header.
Question 3What is required for a LAN switch to support 802.1q Q-in-Q encapsulation?
A. Support less than 1500 MTU
B. Support 1504 MTU or higher
C. Support 1522 layer 3 IP and IPX packet
D. Support 1547 MTU only
Answer: B
Explanation
Because the 802.1Q tunneling feature increases the frame size by 4 bytes when the metro tag is added, you must configure all switches in the service-provider network to be able to process maximum frames by increasing the switch system MTU size to at least 1504 bytes.
Question 4What is the size of the VLAN field inside an 802.1q frame?
A. 8-bit
B. 12-bit
C. 16-bit
D. 32-bit
Answer: B
Explanation
The VLAN ID field inside an 802.1q frame consists of 12 bits. Therefore we have 212 = 4096 VLAN IDs, theoretically.
Question 5What is the maximum number of VLANs that can be assigned to an access switchport without a voice VLAN?
A. 0
B. 1
C. 2
D. 1024
Answer: B
Explanation
Each access port can be only assigned to one VLAN via the “switchport access vlan ” command.
Question 6What does the command “vlan dot1q tag native” accomplish when configured under global configuration?
A. All frames within the native VLAN are tagged, except when the native VLAN is set to 1.
B. It allows control traffic to pass using the non-default VLAN.
C. It removes the 4-byte dot1q tag from every frame that traverses the trunk interface(s).
D. Control traffic is tagged.
Answer: D (in fact no correct answer)
Explanation
This command is used to enable tagging of native VLAN frames on all 802.1Q trunk ports.
Answer A is not correct because even when the native VLAN is set to 1, all of the frames of the native VLAN are tagged.
Answer B is not correct because the control traffic still passes via the default VLAN (VLAN 1).
Answer C is not correct because all the frames are tagged with 4-byte dot1Q tag.
Answer D is not correct as “Control traffic continues to be accepted as untagged on the native VLAN on a trunked port, even when the vlan dot1q tag native command is enabled” according to this link: https://www.cisco.com/c/m/en_us/techdoc/dc/reference/cli/nxos/commands/l2/vlan-dot1q-tag-native.html
Question 7
Interfaces are assigned to a VLAN, and then the VLAN is deleted. Which state are these interfaces in after the VLAN is deleted?
A. They remain up, but they are reassigned to the default VLAN.
B. They go down until they are reassigned to a VLAN.
C. They go down, but they are reassigned to the default VLAN.
D. They remain up, but they are reassigned to the native VLAN.
Answer: B
Explanation
When you delete a VLAN, any LAN ports configured as access ports assigned to that VLAN become inactive. The ports remain associated with the VLAN (and inactive) until you assign them to a new VLAN.
Question 8
Which feature is automatically configured when an administrator enables a voice VLAN?
A. 802.1Q trunking
B. PortFast
C. QoS
D. private VLANs
Answer: B
Explanation
The PortFast feature is automatically enabled when voice VLAN is configured. When you disable voice VLAN, the PortFast feature is not automatically disabled.
Question 9
Question about voice VLAN?
A. Disable by default
B. enter on
C. CoS value of 5
D. Need manually enable
Answer: A C
Question 10
Behavior of an access port when a tagged packet is received other than the access VLAN value.
A. ?
B. tag is removed and packet is forwarded of the VLAN mentioned in the tag
C. packet is dropped
D. tag is removed and packet is forwarded on the VLAN of the access port