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LACP with STP Sim

March 12th, 2017 in Lab Sim, LabSim Go to comments

Question

You work for SWITCH.com. They have just added a new switch (SwitchB) to the existing network as shown in the topology diagram.

LACP_STP_topology.jpg

RouterA is currently configured correctly and is providing the routing function for devices on SwitchA and SwitchB. SwitchA is currently configured correctly, but will need to be modified to support the addition of SwitchB. SwitchB has a minimal configuration. You have been tasked with competing the needed configuring of SwitchA and SwitchB. SwitchA and SwitchB use Cisco as the enable password.

Configuration Requirements for SwitchA

– The VTP and STP configuration modes on SwitchA should not be modified.
– SwitchA needs to be the root switch for vlans 11, 12, 13, 21, 22 and 23. All other vlans should be left are their default values.

Configuration Requirements for SwitchB

– Vlan 21, Name: Marketing, will support two servers attached to fa0/9 and fa0/10
– Vlan 22, Name: Sales, will support two servers attached to fa0/13 and fa0/14
– Vlan 23, Name: Engineering, will support two servers attached to fa0/15 and fa0/16
– Access ports that connect to server should transition immediately to forwarding state upon detecting the connection of a device.
– SwitchB VTP mode needs to be the same as SwitchA.
– SwitchB must operate in the same spanning tree mode as SwitchA.
– No routing is to be configured on SwitchB.
– Only the SVI vlan 1 is to be configured and it is to use address 192.168.1.11/24.

Inter-switch Connectivity Configuration Requirements:

– For operational and security reasons trunking should be unconditional and Vlans 1, 21, 22 and 23 should tagged when traversing the trunk link.
– The two trunks between SwitchA and SwitchB need to be configured in a mode that allows for the maximum use of their bandwidth for all vlans. This mode should be done with a non-proprietary protocol, with SwitchA controlling activation.
– Propagation of unnecessary broadcasts should be limited using manual pruning on this trunk link.

Note: There is a requirement that the trunk between SwitchA and SwitchB must be configured under physical interfaces, not logical port-channel interface

Answer and Explanation:

We post the initial configuration of Sw-A & Sw-B here for your reference, you can try solving this sim by yourself before reading the asnwers below:

Initial Configuration (useless lines have been removed)

SwA:
hostname Sw-A
!
vtp mode transparent
!
spanning-tree mode rapid-pvst
!
vlan 98
!
vlan 99
 name TrunkNative
!
interface FastEthernet0/1
 switchport access vlan 98
 switchport mode access
!
interface FastEthernet0/3
 switchport access vlan 98
 switchport mode access
!
interface FastEthernet0/4
 switchport access vlan 98
 switchport mode access
!
interface Vlan1
 no ip address
 shutdown
!
end
Sw-B:
hostname Sw-B
!
vtp mode server
!
spanning-tree mode pvst
!
interface FastEthernet0/3
!
interface FastEthernet0/4
!
interface FastEthernet0/9
!
interface FastEthernet0/10
!
interface FastEthernet0/13
!
interface FastEthernet0/14
!
interface FastEthernet0/15
!
interface FastEthernet0/16
!
interface Vlan1
 no ip address
 shutdown
!
ip default-gateway 192.168.1.1
!
end

Solution

SW-A (close to router)
Note: If Sw-A does not have Vlan 11, 12, 13 we have to create them first with command “SW-A(config)#vlan 11,12,13”
SW-A(config)#vlan 21
SW-A(config)#vlan 22
SW-A(config)#vlan 23
SW-A(config)#spanning-tree vlan 11-13,21-23 root primary

SW-A(config)#interface range fa0/3 – 4
SW-A(config-if)#no switchport mode access
SW-A(config-if)#no switchport access vlan 98 (These two commands must be deleted to form a trunking link)
SW-A(config-if)#switchport trunk encapsulation dot1q
SW-A(config-if)#switchport mode trunk
SW-A(config-if)#switchport trunk native vlan 99
SW-A(config-if)#switchport trunk allowed vlan 1,21-23
SW-A(config-if)#channel-group 1 mode active
SW-A(config-if)#channel-protocol lacp
SW-A(config-if)#no shutdown

Note: In practical when you apply commands under “interface port-channel 1”, the same commands will be automatically applied to the physical member interfaces (of port-channel 1) so you don’t need to type them under physical member interfaces again. But in this exam you should configure everything under physical interfaces as there is a requirement to do so.

——————————————————————————————–

SW-B (far from router)
SW-B(config)#vlan 21
SW-B(config-vlan)#name Marketing
SW-B(config-vlan)#exit

SW-B(config)#vlan 22
SW-B(config-vlan)#name Sales
SW-B(config-vlan)#exit

SW-B(config)#vlan 23
SW-B(config-vlan)#name Engineering
SW-B(config-vlan)#exit
SW-B(config)#vlan 99
SW-B(config-vlan)#name TrunkNative // not necessary to name it but just name it same as SwitchA
SW-B(config-vlan)#exit
SW-B(config)#interface range fa0/9 – 10
SW-B(config-if-range)#switchport mode access
SW-B(config-if-range)#switchport access vlan 21
SW-B(config-if-range)#spanning-tree portfast
SW-B(config-if-range)#no shutdown
SW-B(config-if-range)#exit

SW-B(config)#interface range fa0/13 – 14
SW-B(config-if-range)#switchport mode access
SW-B(config-if-range)#switchport access vlan 22
SW-B(config-if-range)#spanning-tree portfast
SW-B(config-if-range)#no shutdown
SW-B(config-if-range)#exit

SW-B(config)#interface range fa0/15 – 16
SW-B(config-if-range)#switchport mode access
SW-B(config-if-range)#switchport access vlan 23
SW-B(config-if-range)#spanning-tree portfast
SW-B(config-if-range)#no shutdown
SW-B(config-if-range)#exit

SW-B(config)#vtp mode transparent

SW-B(config)#spanning-tree mode rapid-pvst //Same as Sw-A

SW-B(config)#ip default-gateway 192.168.1.1 (you can get this IP from SW-A with command show cdp neighbour detail) // not sure about this command because the question says “No routing is to be configured on SwitchB”.

SW-B(config)#interface vlan 1
SW-B(config-if)#ip address 192.168.1.11 255.255.255.0
SW-B(config-if)#no shutdown
SW-B(config-if)#exit

SW-B(config)#interface range fa0/3 – 4
SW-B(config-if)#switchport trunk encapsulation dot1q
SW-B(config-if)#switchport mode trunk
SW-B(config-if)#switchport trunk native vlan 99 //this command will prevent the “Native VLAN mismatched” error on both switches
SW-B(config-if)#switchport trunk allowed vlan 1,21-23
SW-B(config-if)#channel-group 1 mode passive //mode passive because “SwitchA controlling activation”
SW-B(config-if)#channel-protocol lacp
SW-B(config-if)#no shutdown

Note: For Sw-B we have to set the 802.1q trunking protocol (switchport trunk encapsulation dot1q) before converting it into a trunk because it is a 3500 series (or higher) switch which supports both ISL and 802.1Q and we have to explicitly set which trunking protocol to be used. Sw-A is a 2900x series (or lower) switch and does not support ISL trunking protocol (802.1Q is the only supported trunking protocol) so we can apply “switchport mode trunk” directly.

———————————————————

Some guidelines for configuring SwitchA & SwitchB:

Configuration Requirements for SwitchA

– The VTP and STP configuration modes on SwitchA should not be modified.
– SwitchA needs to be the root switch for vlans 11, 12, 13, 21, 22 and 23. All other vlans should be left are their default values
SW-A(config)#spanning-tree vlan 11-13,21-23 root primary

Configuration Requirements for SwitchB

– Vlan 21, Name: Marketing, will support two servers attached to fa0/9 and fa0/10
– Vlan 22, Name: Sales, will support two servers attached to fa0/13 and fa0/14
– Vlan 23, Name: Engineering, will support two servers attached to fa0/15 and fa0/16
– Access ports that connect to server should transition immediately to forwarding state upon detecting the connection of a device.
vlan …
name …
(VLANs must be created on both switches if not exist)
interface range fa0/x – y
switchport mode access
switchport access vlan
spanning-tree portfast
– SwitchB VTP mode needs to be the same as SwitchA. vtp mode transparent
– SwitchB must operate in the same spanning tree mode as SwitchA. spanning-tree mode rapid-pvst
– No routing is to be configured on SwitchB.
– Only the SVI vlan 1 is to be configured and it is to use address 192.168.1.11/24.
interface vlan 1
ip address 192.168.1.11 255.255.255.0

Inter-switch Connectivity Configuration Requirements:

– For operational and security reasons trunking should be unconditional and Vlans 1, 21, 22 and 23 should tagged when traversing the trunk link.
– The two trunks between SwitchA and SwitchB need to be configured in a mode that allows for the maximum use of their bandwidth for all Vlans. This mode should be done with a non-proprietary protocol, with SwitchA controlling activation.
– Propagation of unnecessary broadcasts should be limited using manual pruning on this trunk link.
SW-A(config)#interface range fa0/3 – 4
SW-A(config-if)#no switchport mode access
SW-A(config-if)#no switchport access vlan 98
Note: Two above commands must be deleted first to form a trunking link.

Although the first requirement asks us to configure trunking but we can ignore this task because we only need to configure trunking under their Port-channel (in the next task)

– The two trunks between SwitchA and SwitchB need to be configured in a mode that allows for the maximum use of their bandwidth for all Vlans:
SW-A(config)#interface range fa0/3 – 4
SW-A(config-if)#no switchport mode access
SW-A(config-if)#no switchport access vlan 98
SW-A(config-if)#switchport trunk encapsulation dot1q
SW-A(config-if)#channel-group 1 mode active
SW-A(config-if)#channel-protocol lacp
SW-A(config-if)#no shutdown
– Trunking should be unconditional and Vlans 1, 21, 22 and 23 should tagged when traversing the trunk link:
SW-A(config-if)#switchport mode trunk //unconditional trunking
SW-A(config-if)#switchport trunk native vlan 99 //this command will prevent the “Native VLAN mismatched” error on both switches and make other VLANs to be tagged
– Propagation of unnecessary broadcasts should be limited using manual pruning on this trunk link.
SW-A(config-if)#switchport trunk allowed vlan 1,21-23
—————————————
SW-B(config)#interface range Fa0/3 – 4
SW-B(config-if)#switchport trunk encapsulation dot1q
SW-B(config-if)#switchport mode trunk
SW-B(config-if)#switchport trunk native vlan 99 //this command will prevent the “Native VLAN mismatched” error on both switches
SW-B(config-if)#switchport trunk allowed vlan 1,21-23
SW-B(config-if)#channel-group 1 mode passive
SW-B(config-if)#channel-protocol lacp
SW-B(config-if)#no shutdown

Some notes for this sim:
+ You should check the initial status of both switches with these commands: show vtp status (transparent mode on SwitchA and we have to set the same mode on SwitchB), show spanning-tree [summary] (rapid-pvst mode on SwitchA and we have to set the same mode on SwitchB), show vlan (check the native vlan and the existence of vlan99), show etherchannel 1 port-channel and show ip int brief (check if Port-channel 1 has been created and make sure it is up), show run (to check everything again).
+ When using “int range f0/x – y” command hit space bar before and after “-” otherwise the simulator does not accept it.
+ You must create VLAN 99 for the SwitchB. SwitchA already has VLAN 99 configured.
+ At the end, you can try to ping from SwitchB to RouterA (you can get the IP on RouterA via the show cdp neighbors detail on SwitchA), not sure if it can ping or not. If not, you can use the “ip default-gateway 192.168.1.1” on SwitchB.
+ The name of SwitchA and SwitchB can be swapped or changed so be careful to put your configuration into appropriate switch.

Other lab-sims in this site:

MLS and EIGRP Sim
VTP Lab 2
VTP Lab
Spanning Tree Lab Sim
AAAdot1x Lab Sim

Comments
Comment pages
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  1. Star_Shile
    July 27th, 2018

    Doesn’t it require adding native vlan (VLAN99) in trunk; after all it is management vlan

  2. 300-115
    July 29th, 2018

    with regards to the sticky question:
    The question says : ” ….after the PC is moved, port security is cleared on new port”.

    that means when pc connected, the old port was still using the mac in the configuration. see example from GNS3:

    interface Ethernet0/0
    switchport mode access
    switchport port-security
    switchport port-security mac-address sticky
    switchport port-security mac-address sticky 0050.7966.6802
    duplex auto

    after the pc is moved, the admin removes the port-security command from the new interface, but the sticky command is still there:

    !
    interface Ethernet0/3
    switchport mode access
    switchport port-security mac-address sticky
    duplex auto

    so what does that mean for the answers. correct answers are:

    port security sticky exists on the new network switch port
    port security sticky is still enabled on the older network switch port

    the rest of the answers don’t make sense. let’s check:

    port security sticky is disabled on the new network switch port ? no it’s not. command is still there.

    port security must be disabled on all access ports ? why ???? doesn’t make sense.

    port security is still enabled on the older network switch port ? it can be, but it’s all about the sticky part that makes the new port go into err-disabled state.

    IOU3#sh port-security interface e0/3
    Port Security : Disabled
    Port Status : Secure-shutdown
    Violation Mode : Shutdown
    Aging Time : 0 mins
    Aging Type : Absolute
    SecureStatic Address Aging : Disabled
    Maximum MAC Addresses : 1
    Total MAC Addresses : 0
    Configured MAC Addresses : 0
    Sticky MAC Addresses : 0
    Last Source Address:Vlan : 0050.7966.6802:1
    Security Violation Count : 1

  3. Anonymous
    July 29th, 2018

    does anyone have packet tracer similar file..

  4. examonfriday
    August 1st, 2018

    Regarding the native 99 or native 1 debate.
    The task says “Vlans 1, 21, 22 and 23 should tagged”
    That can be achieved in two ways:
    -Change native vlan to something else (like 99 above)
    -Use the “vlan dot1q tag native” in global config mode to tag native vlan on both switches

    But of course first make sure the native vlan is the same on both switches.

  5. examonfriday
    August 1st, 2018

    The tag native option is only in that case if you would like to keep Vlan1 as native

  6. VLAD
    August 3rd, 2018

    Sim is valid, but during my exam all ports of SWB were down. Anyone experienced the same? I passed the exam with 8XX.

  7. an
    August 4th, 2018

    @vlad
    Yes, I had the same ports down.
    And btw no native mismatch (like in earlier versions), so the only reason I had to change native vlan was because of the task to send VLAN1 as tagged over the trunk.

  8. Kush
    August 7th, 2018

    I passed yesterday with 825points CCNP Switch, from LABS in exam was this LAB edhe AAAdot1x LAB

  9. xelo
    August 12th, 2018

    Does anyone have the latest dumps for Switch.

  10. mosx
    August 13th, 2018

    Is the command
    Switch A(config)# default interface range fa0/3-4
    valid?

    Thanks for the answer.

  11. Anonymous
    August 13th, 2018

    Does anyone have the latest dumps for Switch

  12. Anonymous
    August 14th, 2018

    I have a question about the communication between SWITCH B and Router.
    The SWITCH A fa0/1 and Router f0/0 were configured as access vlan 98 and SWITCH A is not Router.
    How can SWITCH B (vlan 1) get a connection with Router?

    Thanks for the answer.

  13. RED1
    August 16th, 2018

    I passed today successfully
    I have been asked for this LAB LACP with STP

    All is right, I did it like this site.
    No ip routing command is needed
    At the end
    show ip inter brief
    the ether channel was UP
    And i could ping the router: 192.168.1.1

  14. Anonymous
    August 16th, 2018

    it was part of my exam today…

  15. Red1
    August 17th, 2018

    INSTATNT DOWNLOAD here

    200-125 CCNA = 486
    100-105 ICND1 = 347
    200-105 ICND2 = 268

    300-101 ROUTE = 146 SP0T0
    300-115 SWITCH = 831
    300-135 TSHOOT = 101

    400-101 WRITTEN = 248

    Copy below link:
    http://www.yumpu.com/xx/embed/view/fkSIdylaC9co2z7v

  16. sancho
    August 19th, 2018

    if it says configure the port channel on the physical interface they dont want you to configure anything on the port channel, however ive seen that the only way to get rid of the native vlan mismatch error is to configure the native vlan on po1.

    Can someone clarify?

  17. Hello_CCNP
    August 19th, 2018

    In real exam does these labs get you partial points or do you have to have the entire lab correct?

  18. Hello_CCNP
    August 19th, 2018

    I found some chatters on Google that you do get partial points, just want to confirm. Can anyone confirm that here? thanks.

  19. Hello_CCNP
    August 19th, 2018

    Same here @sancho. I am assuming simply follow the lab for now. In real world, you will configure the port channel first anyway and ports part of that channel will automatically apply anything on that port channel. At least that’s what I found out.

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