ICND2 – DTP Questions
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Question 1
[am4show have=’p2;’]Which statement about DTP is true?
A. It uses the native VLAN.
B. It negotiates a trunk link after VTP has been configured.
C. It uses desirable mode by default.
D. It sends data on VLAN 1.
Answer: D[/am4show]
Explanation
Control traffic like CDP, DTP, PAgP, and VTP uses VLAN 1 to operate, even if you change the native VLAN.
Question 2
[am4show have=’p2;’]How can you disable DTP on a switch port?
A. Configure the switch port as a trunk.
B. Add an interface on the switch to a channel group.
C. Change the operational mode to static access.
D. Change the administrative mode to access.
Answer: A (no correct answer, in fact)[/am4show]
Explanation
Although some books and websites said DTP is disabled if the switch port is configured as trunk or access mode (via the command “switchport mode trunk” or “switchport mode access”) but in fact DTP is still running in these modes. Please read at http://packetlife.net/blog/2008/sep/30/disabling-dynamic-trunking-protocol-dtp/. The only way to disable DTP on a switch port is to use the “switchport nonegotiate” command. But notice this command can only be used after configuring that switch port in “trunk” or “access” mode.
Therefore this is a question with no correct answer but if we have to choose an answer, we will choose answer A. At least it is correct in theory.
Question 3
[am4show have=’p2;’]Which three statements about DTP are true? (Choose three)
A. It is enabled by default.
B. It is a universal protocol.
C. It is a proprietary protocol.
D. It is disabled by default.
E. It is a Layer 3-based protocol.
F. It is a Layer 2-based protocol.
Answer: A C F[/am4show]
Question 4
[am4show have=’p2;’]What is the DTP’s default mode in a switch?
A. ON
B. OFF
C. Dynamic Desirable
D. Dynamic Auto
Answer: D[/am4show]
Explanation
The Dynamic Trunking Protocol (DTP) is used to negotiate forming a trunk between two Cisco devices.
In fact this question is unclear as it does not ask about a specific switch model. The default DTP configuration for Cisco Catalyst 2960 and 3560 switches is dynamic auto while older 3550 switches run Dynamic Desirable as the default mode. So in this question we should follow the “newer” switches (which is “dynamic auto” mode).
New switches are only set to “dynamic auto” mode by default so they are safer as they do not try to form a trunk aggressively.
Therefore in this question “dynamic auto” is the best choice.
Reference: http://www.ciscopress.com/articles/article.asp?p=2181837&seqNum=8
Is the answer to question 2
trunk or access?
(i am not able to see the questions currently)
in regards to Q 1, I thought CDP, DTP traveled on the native VLAN.
Because if ‘Control traffic like CDP, DTP, PAgP, and VTP uses VLAN 1 to operate, even if you change the native VLAN.’ is true. When you shut VLAN 1 would you no longer see CDP neigh??
So Maria,
Were the 9tut dumps any use to you?
Is question 1 not Native Vlan??
you can’t shutdown vlan 1 or suspend
But you can prune vlan 1 from a trunk; in which case I’m pretty sure cdp still works. I’ll have to research.
No, only VLAN0001 for control traffic, no matter what you do, including pruning with VTP, according to this at least:
https://supportforums.cisco.com/discussion/10790041/shutting-down-vlan1-security-switchport-trunk-native
For question 4, option D (Dynamic Auto) is correct for Catalyst 2960 and 3560 but option C (Dynamic desirable) is correct for older Catalyst 2950 and 3550 switches as stated in the link provided under question 4 explanation. The question states “Whats DTP’s default in a switch?”. How can option D be correct when we dont know which series switch it is?
Anyone done the exam lately?
I have mine next friday
Hi,
for question 2 I have found this
https://supportforums.cisco.com/discussion/12915416/change-dynamic-auto-access-mode-will-disable-dtp-effectively
my understanding is that the correct answer is D.
If configured as trunk you need also the command switchport nonegotiate. Any thought on this?
I had question 4 modified today on icnd2 the choices were:
What is DTP’s default in a switch?
A. ON
B. OFF
C. Desirable
D. Auto
Is it Auto or ON?
@kksmh
DTP default mode?
Older devices were auto, newer devices are desirable. Cisco changed this to make it a bit more secure. I would go with desirable as the correct answer.
Is anyone having troubles seeing the questions
Question 2’s answer is D. When you configure the interface in Access mode it stops negotiating the trunk (show interface switchport), even if some DTP packets are still being sent by the interface.
se repiten las preguntas 1 con la 5.. por que?
se repiten las preguntas 1 con la 5.. por que?
I would definitely go for answer D on question 2 – putting the interface into switchport mode access will stop DTP
Q2. How can you disable DTP on a switch port?
Switchport Mode Access: This puts the interface (ACCESS PORT) into a PERMANENT NON-TRUNKING mode and negotiates to convert the link into a NON-TRUNK link. The port would be a dedicated Layer 2 access port!
Switchport Nonegotiates: Prevents the interface from generating DTP Frames. You can use this command only when the interface switchport mode is (ACCESS/TRUNK).
https://drive.google.com/open?id=0B5mAFqgydmCzNno3dnFocF9HckU has the dumps for CCNA
Q4 and Q7 (default mode for DTP) counteract each other. Please clarify, and remove the question that reflects the wrong answer.
For what it’s worth, my research indicates the DTP default can change based on the type of switch you are using. For a Cisco IOS switch: “By default, a Cisco Ethernet port’s default DTP mode is “dynamic desirable”, which allows the port to actively attempt to convert the link into a trunk.” — probably the best answer for current testing. (Note: For a Cisco ILS switch, the default is Auto.)
As far as disabling DTP, I found this information:
nonegotiate = Sets Trunking on and disables DTP. These will only become Trunks with ports in on or nonegotiate mode.
off = This option sets Trunking and DTP capabilities off. This is usually the recommended setting for any access port since it prevents any dynamic establishments of Trunk links.
Info found here: https://www.cisco.com/c/en/us/td/docs/net_mgmt/ciscoworks_lan_management_solution/4-2/user/guide/configuration/config/configvlan.html?dtid=osscdc000283
Skunks
Q1.
DTP does not use tagging, so native vlan seem to be the best answer.
@Bengt try out GNS3 academy this is the second post I have seen you wrote that is incorrect dont take this wrong I want you to pass. CDP VTP and DTP all go over vlan 1 regardless if you change the Native Vlan. GNS3 academy covers this topic very well.
Also forgot PAgP
Q 1
On an 802.1Q trunk, DTP packets are sent on the native VLAN.
On an ISL trunk, DTP packets are sent on VLAN1.
Not enough info in the question to answer A or D. For 802.1Q trunk native defaults to VLAN1 but it can be changed and DTP would follow to the changed native VLAN which will no longer be VLAN1.
https://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/24330-185.html#pre6
search for: “DTP packets”
https://supportforums.cisco.com/t5/lan-switching-and-routing/disable-dtp-on-a-switch/td-p/3328521
Question 2 after putting some time and deep digging I will say A is the answer. here is why. there is no such command to change administrative mode. status will only change when switch between access or trunk. if we go by D then C is also correct. again there is no such command to change operational mode it only change when switch between access or trunk by entering command switchport mode assess or trunk. so D and C is out B is already out too~ have fun~
How can you disable DTP on a switch port?
A. Configure the switch port as a trunk.
B. Add an interface on the switch to a channel group.
C. Change the operational mode to static access.
D. Change the administrative mode to access.
Answer: A
Question 2 states:
Q: How can you disable DTP on a switch port?
Answer per Cisco Employee: switchport nonegotiate
https://supportforums.cisco.com/t5/lan-switching-and-routing/switchport-nonegotiate-sets-trunking-on-and-disables-dtp/td-p/1649235
9tut.net
Mam/Sir,
Please add this as an option above.
Thank You.
We appreciate you and this site for teaching foundations to build from and to practice.
@youknowwho: We know this command will disable DTP but it is not an option of this question in the exam.
There are only three answers in the Quiz:
OFF
Dynamic desirable
ON
whats the correct?
Confirming the 398q dumps are valid.
Question 2
How can you disable DTP on a switch port?
A. Configure the switch port as a trunk.
B. Add an interface on the switch to a channel group.
C. Change the operational mode to static access.
D. Change the administrative mode to access.
Answer: C
My explanation:
I’ve checked it in the Packet Tracer Simulation Mode.
By default switches send to each other DTP packets.
When you enter the switchport mode access command on one of the switches it start to discard the DTP packets.
And if enter the show interfaces switchport command you will see this:
Switchport: Enabled
Administrative Mode: static access <—
Operational Mode: static access <—
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: native
Negotiation of Trunking: Off <—
——————————————-
If you check how works the command switchport mode trunk you will ses this:
Switch#show interfaces switchport
Name: Fa0/1
Switchport: Enabled
Administrative Mode: trunk <—
Operational Mode: trunk <—
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
Negotiation of Trunking: On <—!
To turn negotiation off you need one more command to enter – switchport nonegotiate and ONLY after that Negotiation of Trunking will become Off and switch stop sending DTP packets.
So when using the static access mode you will get what you need immediately.
These questions aren’t bad to reference. They’ll never be exact but they are for sure…similar.
Question 2 answer IS D.
As somebody said already, ‘nonegotiate’ would have been the best option to choose BUT configuring the interface in access mode will disable DTP negotiation as well, while configuring it in trunk mode will not.
@Doc: good point but wrong answer choice. When you change the configuration you change the Administrative Mode of the interface.
https://learningnetwork.cisco.com/thread/29256
@MN March 13th, 2018: ” there is no such command to change administrative mode. status will only change when switch between access or trunk. if we go by D then C is also correct. ”
Sorry but you’re wrong: changes to che configuration of the interface
How can you disable DTP on a switch port?
A. Configure the switch port as a trunk.
B. Add an interface on the switch to a channel group.
C. Change the operational mode to static access
D. Change the administrative mode to access
since ‘nonegotiate’ is not listed, here’s what I found.
DTP negotiation runs on TRUNK for VTP so a is incorrect
one will think the answer is C but there is no command to for that (instead)
to Change the operational mode to static access, the ADMINISTRATIVE MODE HAS TO BE CONFIGURED AS STATIC ACCESS.
this is done by going in to the interface and issue the [switchport mode access]
the command [switchport mode dynamic desirable] won’t work and you’ll get
“Command rejected: Conflict between ‘nonegotiate’ and ‘dynamic’ status.”
so yes, my answer is D.
I passed ICND2 on November 4th with 854! There are 54 questions, 4 drag and drop 2 labs for me EIGRP and GRE, BGP, ACL, IP SLA, RSTP, HSRP, PPPOE Questions! I have all the labs, and the majority of the questions, I have two courses and a lot of labs from CISCO to be prepare write alberthdr AT hotmail point com
For question 2, How can you disable DTP on a switch port?
From what I’ve read there are two ways to disable DTP, and from an architectural perspective, DTP should never be allowed to remain on by default.
The first way is configuring the switchport as an access port by using the command switchport mode access. This will disable DTP and allow the switchport to operate only in the configured VLAN, if none is configured by default it will be placed into VLAN_1.
The second way to disable DTP is by using the command switchport nonegotiate statically configured trunk interfaces. This will ensure that DTP is disabled and static trunking is configured. This is the most common way to configure trunk unlinks between switches to share layer 2 information.
So maybe they are implying that answer A. “Configure the switch port as a trunk.” means that you have used switchport nonegotiate and thus configured static trunking on the port. Thoughts?