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VTP Questions 3

September 15th, 2017 in SWITCH 300-115 Go to comments

Question 1


During switch boot up, the switch compares the content in the vlan.dat file and the configuration in startup-config to determine if it should use the configuration in vlan.dat or startup-config. When you save VTP mode, domain name, and VLAN configurations in the switch startup configuration file and reboot the switch, the VTP and VLAN configurations are selected by these conditions:
+ If both the VLAN database and the configuration file show the VTP mode as transparent and the VTP domain names match, the VLAN database is ignored. The VTP and VLAN configurations in the startup configuration file are used. The VLAN database revision number remains unchanged in the VLAN database.
+ If the startup VTP mode is server mode, or the startup VTP mode or domain names do not match the VLAN database, VTP mode and VLAN configuration for the first 1005 VLANs are selected by VLAN database information, such as the vlan.dat file. VLANs greater than 1005 are configured from the switch configuration file (startup-config file).

Reference: http://www.cisco.com/c/en/us/support/docs/switches/catalyst-2940-series-switches/109304-manage-vlandat.html

Question 2

Question 3

Question 4


VTP pruning should only be enabled on VTP servers, all the clients in the VTP domain will automatically enable VTP pruning -> C is correct.

Question 5


In fact this is an unclear question. VLAN 1 (and VLANs 1002 to 1005) are always pruning-ineligible (even when VLAN 1 is not the native VLAN) so answers C D are not correct.

But answers A and B are not correct too as VLANs 2 through 9 are pruned (at least on SW1).

Maybe the author of this question forgot that VLAN 1 is pruning-ineligible. If so the best choice should be C.

Question 6


In addition to propagating VTP information, version 3 can propagate Multiple Spanning Tree (MST) protocol database information. A separate instance of the VTP protocol runs for each application that uses VTP -> Only VTPv3 supports multiple VTP instances -> Answer A is not correct.

VTP version 1 and version 2 support only normal-range VLANs (VLAN IDs 1 to 1005). VTP version 3 supports the entire VLAN range (VLANs 1 to 4094). Extended range VLANs (VLANs 1006 to 4094) are supported only in VTP version 3. You cannot convert from VTP version 3 to VTP version 2 if extended VLANs are configured in the domain.

Only VTPv3 allows to turn on/off per-port basis -> Answers C, E are not correct.

Consistency Checks: In VTP version 2, VLAN consistency checks (such as VLAN names and values) are performed only when you enter new information through the CLI or SNMP. Consistency checks are not performed when new information is obtained from a VTP message or when information is read from NVRAM. Therefore answer D is not correct.

Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3560/software/release/12-2_52_se/configuration/guide/3560scg/swvtp.html

Question 7


In VTP versions 1 and 2, the switch must be in VTP transparent mode when you create extended-range VLANs. VTP version 3 also supports creating extended-range VLANs in client or server mode -> Answer A is correct.

Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3560/software/release/12-2_52_se/configuration/guide/3560scg/swvtp.html

Extended-range VLANs range from 1006-4094, inclusive. However, if using VTPv1 or VTPv2, these additional VLANs cannot be configured in VLAN database mode, nor stored in the vlan.dat file, nor advertised through VTP (so answer E is not correct). In fact, to configure them, the switch must be in VTP transparent mode. VTPv3 removes these limitations: Both normal- and extended-range VLANs can be advertised by VTPv3. Also, with VTPv3, information about all VLANs is again stored in the vlan.dat file in Flash -> Therefore VTPv3 stores the extended-range VLAN in VLAN database (vlan.dat file).

Reference: CCIE Routing and Switching v5.0 Official Cert Guide, Volume 1, Fifth Edition

VLAN 1 and VLANs 1002 to 1005 are always pruning-ineligible; traffic from these VLANs cannot be pruned. Extended-range VLANs (VLAN IDs greater than 1005) are also pruning-ineligible -> Answer D is correct.

Reference: https://www.cisco.com/c/en/us/support/docs/lan-switching/vtp/10558-21.html

Question 8


VTP version 3 supports creating extended-range VLANs in client or server mode -> Answer B and D are not correct.

Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3560/software/release/12-2_52_se/configuration/guide/3560scg/swvtp.html

Private VLANs can only be configured when VTP is in transparent/off modes in VTP version 1 or 2 and in server/transparent/off modes in VTP version 3 when pruning is turned off -> Answer A is correct while answer E is not correct.

  1. mikeSWE
    July 19th, 2017

    @Certprepare please confirm q1 here. URGENT exam in 2 days

    Different dumps are all saying B and D is the correct answer

  2. Anonymous
    July 27th, 2017

    A and D

    August 2nd, 2017
  4. BoZZ
    August 14th, 2017

    Question 2 – C and E, not A as password is hidden or secret not hashed nor D as VTPv3 msgs are not encrypted.


  5. Bahati
    September 7th, 2017

    Is the answer here B and C

  6. molesys
    October 2nd, 2017

    can someone explain why in question 5 the answer is “A” and not ” C. VLANs 1 through 9 are pruned on the link between SW1 and SW4 ” ???

  7. molesys
    October 2nd, 2017

    Now I know why!!!, VTP pruning increases available bandwidth by restricting flooded traffic to those trunk links that the traffic must use to access the appropriate network devices. VLAN1 is always ineligible for pruning; traffic from VLAN1 cannot be pruned.

  8. switchy
    October 15th, 2017

    Q5 Can someone explain why the answer is not “A”?

  9. oval
    November 6th, 2017

    @switchy, I believe the answer to Q5 depends on if switch 6 has VTP pruning enable or not.
    If switch 6 have VTP pruning enable, sw1 through sw4 won’t be flooded with vlan range 2-9.
    If switch 6 have VTP pruning disable, then vlan range 1-101 will be flooded in all switches.

    Anyone knows why it’s “A” the correct answer?

  10. Al
    November 11th, 2017

    Q 5
    I would say the answer is option C.
    The traffic on VLAN 1-9 is definitely not flooded between SW1-SW2 and SW1-SW4 as it indicates on the diagram. Now to answer the question that VLAN 1 is pruning ineligible. Yes, but there is no reason why it cannot be removed (pruned) manually with “switchport trunk allowed vlan remove 1” from both sides. I suspect VLANs 1-9 have been pruned manually from the links SW1-SW4 and SW1-SW2, therefore the related traffic will not be flooded on the links. Hence the option C is right. I think “vtp pruning” is just misleading.


  11. Hank
    November 15th, 2017

    For Q5:
    The question may be represented incorrectly. Are the numbers on the links the ALLOWED vlans or the PRUNED vlans? If pruned, then the vlans 1-9 are being flooded because SW6 is the SERVER and is pruning 1-101 in its uplink, and pruning 10-101 on its lateral link. Therefore, vlans 1-9 are flooded out its lateral link and propagated throughout the domain.

    If the numbers represent the ALLOWED vlans, then the correct answer is C.

    Certprepare, can you solve this for us?

  12. oval
    November 16th, 2017

    For Q5,
    Both VLAN 1 and the system VLANs 1002-1005 are never eligible for
    pruning, so C and D.

    I belive the correct answer is “A. Traffic on VLANs 1 through 9 is flooded to all switches in the network” since we have a ring topology, and we have to flood traffic for all vlans in all switches.

  13. bigM
    November 23rd, 2017

    Q7 C & E

  14. RealD
    November 24th, 2017

    Q5. Vlan 1 can’t be pruned. That leaves A and B.

  15. Nick
    November 29th, 2017

    DO NOT USE http://www.myexamcollection.com/ ITS A FAKE

  16. Anonymous
    December 4th, 2017

    For Q5
    Native VLAN can be: Vlan-99
    So Vlan 1 eligible to be pruned !!!
    Then answer is: C

  17. ciptech
    December 4th, 2017

    Question 5

    Refer to the exhibit.

    If switch SW6 is operating VTP Server and the other devices have the same configuration as SW4, which statement about the VLANs network is true?

    SW4# show run | include vtp
    vtp mode client
    vtp domain cisco
    vtp domain ciscotest
    vtp pruning
    vtp version 3

    A. Traffic on VLANs 1 through 9 is flooded to all switches in the network
    B. VLANs 1 through 101 are operational on all switch trunks
    C. VLANs 1 through 9 are pruned on the link between SW1 and SW4
    D. VLANs 1 through 101 are pruned on the link between SW1 and SW2

    We eliminate answer D from the beginning (i hope no doubts here:) ).
    Answer A for me looks incomplete: which kind of traffic is flooded, for sure not ALL.

    We can split the answer like this:
    – if VLAN 1 is Native => C is incorrect => A or B => SW6 is the server, he will update all the others with the active VLANS: 1 to 101 => B

    – if VLAN 1 is not Native => SW6 is the server, he will update all the others with the active VLANS: 1 to 101 => SW1 and SW4 will have all the vlans => no need to prune => B

    Answer B (if answer A is correct => B is also true)

  18. ccnp_switch
    December 5th, 2017


    To provide security, a service provider various private VLANs in its backbone network infrastructure to prevent certain VLANs communicating to each other. Which version of VTP supports the use of private VLANs?
    A. version 1 B. version 3 C. VTP does not support private VLANs D. version 2

    here the answer they say it’s B, but on cisco site it says “• VTP version 3 is not supported on private VLAN (PVLAN) ports. ”

    VTPV3 only propagates the private vlans.

    so which one is it ? :)

  19. HiTmAn47
    December 20th, 2017

    I need an explanation for Question 5 please

  20. Biddu
    December 29th, 2017

    Q5 – option c and d not valid as vlan 1 is not eligible for pruning

    left with option A and B both are correct answers .. keeping in mind this is ring topology

  21. Odie007
    January 10th, 2018

    I think I understand the point of confusion here. However, I find it hard to believe that it would state on any Cisco site that VTP v3 doesn’t support PVLANS.
    Therefore it states the following in the configuration guide:

    “VTP versions 1 and 2 do not support private VLANs. VTP version 3 does support private VLANs. If you configure private VLANs, the switch must be in VTP transparent mode. When private VLANs are configured on the switch, do not change the VTP mode from transparent to client or server mode.”

    The Private VLAN support sounds daunting, but it really does a very simple task. All it does is carry the VLAN associations, it’s not assigning interface or trunk configs anywhere.

    It doesn’t matter where I trunk this, or what ports are applied in what fashion. This is basically all we’re replicating:

    SW1#show vlan private-vlan

    Primary Secondary Type Ports
    ——- ——— —————– ——————————————
    600 601 isolated

    SW2#show vlan private-vlan

    Primary Secondary Type Ports
    ——- ——— —————– ——————————————
    600 601 isolated Fa0/6

    Sources: some ccie blogspot I can’t post here and https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/3se/consolidated_guide/configuration_guide/b_consolidated_3850_3se_cg/b_consolidated_3850_3se_cg_chapter_01101110.html#reference_68E5E86160F24B7C989975B84F037E36

  22. 1WAY
    February 1st, 2018

    Q5. Until it’s clear whether the ranges on the links are ‘pruned vlans’ or ‘allowed vlans’ then the question is nonsense. i think you also need to assume that all other configuration is default (native vlan = 1) as they have’nt stated otherwise.

  23. Archangel
    March 1st, 2018

    Q5 help
    VTP pruning does not prune traffic from VLANs that are pruning-ineligible. VLAN 1 and VLANs 1002 to 1005 are always pruning-ineligible; traffic from these VLANs cannot be pruned. Extended-range VLANs (VLAN IDs greater than 1005) are also pruning-ineligible.

    reference https://www.cisco.com/c/en/us/support/docs/lan-switching/vtp/10558-21.html

  24. George_Bab
    April 25th, 2018

    Q5 make it more clear! As I understand, Native Vlan by default is 1. So as it mentioned before options C & D are not correct. Left option A & B that both for me also is correct. These kind of Questions are tricky.

  25. lalaversa
    May 4th, 2018

    nonsense question and nonsense draw… there is no judicious answer to this question based on the draw and the answer options….

  26. lalaversa
    May 4th, 2018

    Q5. nonsense question and nonsense draw… there is no judicious answer to this question based on the draw and the answer options….

  27. madestro
    May 19th, 2018


    From the limited information that I see on the question we must assume all defaults are configured (that is the way it works with Cisco questions), therefore C and D cannot be right as you cannot prune VLAN 1.
    I would guess (although needs clarification) that the exhibit shows the allowed VLANs passing through that link (nobody really shows the VLANs that are not passing, wouldn’t make much sense), which makes B an incorrect answer.

  28. JB
    May 28th, 2018

    I don’t understand how Q1 is correct.

    If you’re using VLANs greater than 1005 and the VTP mode is server you must used VTP version 3. However when I configure VTP v3 in a lab on a 3560 switch with VLANS higher than 1005 they are not show in the running or startup configuration.

  29. certprepare
    July 27th, 2018

    @all: We have just updated the explanation for Q.5. The best answer should be C (please read the explanation above).

  30. CCNA-AZ
    August 3rd, 2018


    Why answer “A” is not correct? As I know, vlan database stores vlans from 1 to 1005. Then A and C should be equal to each other

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