Question 1
A switch has been configured with the vlan dot1q tag native command. Which statement describes what the switch does with untagged frames that it receive?
A. Untagged frames are forwarded via the default VLAN
B. It drops the untagged frames
C. The trunked port is put in err-disable state
D. Untagged frames are forwarded via the native VLAN
Answer: B
Explanation
The “vlan dot1q tag native” command maintains the tagging on the native VLAN and drop untagged traffic -> B is correct.
Reference: http://www.cisco.com/web/techdoc/dc/reference/cli/nxos/commands/l2/vlan_dot1Q_tag_native.html
Question 2Refer to the exhibit. Which two commands about SW1 are true? (Choose two)
A. Interface Gi5/1 is using a Cisco proprietary trunking protocol
B. On interface Gi5/1, all untagged traffic is tagged with VLAN 113
C. The device is configured with the default MST region
D. Interface Gi5/1 is using an industry standard trunking protocol
E. Interface Gi6/2 is the root port for VLAN 36
F. On interface Gi6/2, all untagged traffic is tagged with VLAN 600
Answer: C D
Explanation
Interface Gi5/1 is using 802.1q trunking which is an open standard protocol -> A is not correct while D is correct.
From the output we see the native VLAN of Gi5/1 interface is VLAN 1 so all untagged traffic should belong to VLAN 1 (using the default setting) -> B is not correct.
In this question we can only guess that “The device is configured with the default MST region” (also referred to as IST or Internal Spanning Tree). The “show interface trunk” command does not display any information about MST.
Answer E may be correct as interface Gi6/2 is in forwarding state for VLAN 36 so it may be the root port for VLAN 36.
So in conclusion there are two possibly correct answers but we have to choose one. We believe answer C is better than E so we choose it the best answer left.
Note: Answer F is not correct because VLAN 600 is the native VLAN on Gi6/2 does not mean untagged traffic is tagged with this VLAN. It only means “all untagged traffic belongs to VLAN 600”.
Question 3
Question about trunk configuration
int faX/X
switchport trunk allowed vlan x,x,x,x
switchport mode trunk
exit
show vlan
VLAN Name Status Ports
—- ——————————– ——— ——————————-
1 default active Fa0/1, Fa0/3, Fa0/3, FaX/X
show interface trunk
(no output)
A. link is shutdown
B. interface needs no shutdown
C. other side is configured as access port
D. missing switchport command
Answer: ? (maybe A)
Question 4
Which two DTP negotiated interface mode combinations negotiate to form an access port? (Choose two)
A. Dynamic desirable and Dynamic Auto
B. Dynamic Desirable and access
C. Dynamic auto and Dynamic auto
D. Nonegotiate and trunk
E. Dynamic auto and trunk
Answer: B C
Explanation
From the summary in the book of “Cisco Press’ SWITCH Foundation Learning Guide”:
We see an access port is formed when:
+ Both ports are in “Dynamic Auto”
+ One port in “Dynamic Auto” and the other port in “Access”
+ One port in “Dynamic Desirable” and the other port in “Access”
+ Both ports are in “Access”
Note: If you want to know what the result if one of the port is in “Nonegotiate” mode then this is the table you want:
Question 5
Which two configurations can you apply to a port so that it tags traffic with VLAN 915? (Choose two)
A.
interface GigabitEthernet0/0
switchport mode access
switchport access vlan 915
B.
interface GigabitEthernet0/0
switchport mode trunk
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 915
C.
interface GigabitEthernet0/0
switchport mode access
switchport voice vlan 915
switchport access vlan 915
D.
interface GigabitEthernet0/0.915
encapsulation dot1q 915
E.
interface GigabitEthernet0/0.915
switchport mode access
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 915
Answer: B D
Question 6
Refer to the exhibit. Which statement about the interface is true?
A. The interface is down.
B. The other side of the interface is set as access.
C. The switchport command is missing from the configuration.
D. The interface needs no shutdown configured.
Answer: A
Explanation
Although Gi0/10 has been configured as trunk it it did not appear in the “show interfaces trunk” command so the most suitable reason is it is down (not administratively down but down for another reason).
Question 7
Refer to the exhibit. Which description of the effect of entering the switch port trunk allowed vlan 2,3,4 command on FastEthernet0/2 is true?
A. The two workstations continue to communicate without a default gateway configured.
B. The command is unsupported on a trunk where VLANs have already been pruned manually.
C. The running configuration displays switch port trunk allowed vlan 1-5 for Fa0/2.
D. The two workstation stop communicating because they are on VLAN 5.
Answer: D
Explanation
By entering the command “switch port trunk allowed vlan 2,3,4”, vlan 5 would be removed from allowed VLAN list. Both Workstations A & B are on VLAN 5 so they cannot communicate any more.
Note: If we want to add vlan 2 to 4 to the allowed VLAN list then we should use the “switchport trunk allowed vlan add 2,3,4”.
Question 8
How can you set VLAN 99 on a trunk to become a native VLAN?
A. switchport trunk native vlan 99
B. switchport trunk vlan 99 native
C. switchport native vlan 99 trunk
D. switchport native trunk vlan 99
E. switchport vlan 99 native
F. switchport vlan native trunk 99
Answer: A
Question 9
If VLAN 99 is set to trunk, how can you set it to untagged from trunk VLAN 99?
A. switchport access vlan 99
B. switchport vlan 99 access
C. switchport vlan 99 allow access
D. switchport allow access vlan 99
Answer: A
Question 10
Which command configures VLAN 99 as an untagged VLAN on a trunk?
A. switchport access vlan 99
B. switchport trunk pruning vlan except 99
C. switchport trunk allowed vlan 99
D. switchport trunk native vlan 99
Answer: D