LACP with STP Sim
Question
You work for SWITCH.com. They have just added a new switch (SwitchB) to the existing network as shown in the topology diagram.
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 //Some reports say that this command does not work on SW-A so just ignore it
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)#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: |
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.
The following “show” commands should be used to verify the configuration:
+ show vlan (check if the VLANs and VLAN names are correct)
+ show interface trunk (check if physical and port-channel is in trunking mode; the native VLANs on two switches match; allowed VLANs are correct)
+ show etherchannel summary (check Etherchannel status and LACP mode)
+ show ip interface brief (make sure the configured ports are up/up)
+ show spanning-tree (check STP mode)
+ show spanning-tree detail (can be used to check PortFast on specific interface but not sure if this command is supported in the exam)
+ show vtp status
+ show run (verify everything again)
Other lab-sims in this site:
MLS and EIGRP Sim
VTP Lab 2
VTP Lab
Spanning Tree Lab Sim
AAAdot1x Lab Sim
Please, where can I find the packet tracer files for the labs?
@abdullah so, the command interface range is available in this lab, but i need to use space between interfaces identifier.
Correct: interface range fa0/3 – 4
Wrong: interfface range fa0/3-4
why the show command interface trunk doesn’t show anything
Need Help
%CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on Port-channel 1 (1), with Sw_A FastEthernet0/4 (99).
i did all configuration many time. but above error come. how i will solve this issue need help.
TIA
sroosh if you dont have any operational trunks, it won’t show anything
sk make sure each side has the native vlan set
I have a question, in this Lab, certprepare say that we need to put the configuration of the etherchannel directly in the interfaces fa0/3 – 4, but it also say that we should check if switch A has the port-channel created, if it has the port-channel created, we should ignore it and put the configuration on the interfaces or put the configuration on the port-channel?
Hi
can you please share dump file ermanozcan @ gmail . com
“Note: There is a requirement that the trunk between SwitchA and SwitchB must be configured under physical interfaces, not logical port-channel interface”
Later:
“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)”
So which is which? Do we have to configure trunking under the physical interfaces or under the port-channel interface?? In the Packet Tracer lab solutions the trunk is configured under both physical and Po1 interfaces.
Configure on physical interfaces and port channel. I passed this exam 3 years ago and I did both and got full points…
@ supportdonkey
Thanks, much appreciated.
Pass 300-115 on 16/10/2019.
This question is still there.
Good luck to all of you!
In this laboratory when I do it in packet tracert I have several problems.( switches 2960 )
1st – when I try to put no switchport mode access in Switch A “no switchport mode access” packet tracert shows an error Command rejected: An interface must be configured to the Access or Trunk modes to be configured to NoNegotiate …
On the other hand I observe that when you create the interface range fa0 / 3-4 on both switches:
….
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
The interface of the portchannel po1 has nothing in its configuration appears empty, however in the physical interfaces if it appears with all the configurations. the same configurations must be added by hand within the po1 interface so that it does not work?
I mean once I set the configuration above to fa0 / 3-4, then you have to enter the po1 interface and do the same thing:
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
because otherwise I don’t see him lift the trunk …
Have latest 300-101 Route dumps and wanna get Switch dumps. My email: {email not allowed} , just send me switch dumps and I will send route dumps in response! Thanks!
Have latest 300-101 Route dumps and wanna get Switch dumps. My email: azekamranabdullayev @ gmail.com , just send me switch dumps and I will send route dumps in response! Thanks!
@ SK
you will keep getting that error unless you configure your port-channel group 1 as trunk and set native as 99.
on both switches and apply the config below, you will stop getting that err-message
!
interface Port-channel1
switchport trunk native vlan 99
switchport mode trunk
!
“For operational and security reasons trunking should be unconditional and Vlans 1, 21, 22 and 23 should tagged when traversing the trunk link.”
I get that the running config has vlan 99 with the name of TrunkNative but it concerns me that it isn’t written in the question. Cisco being Cisco, does anyone else think that the possible answer might be: “vlan dot1q tag native”? I feel like they would explictly say what the native vlan should be if that’s what they wanted.
In addition, you send up creating VLAN 99 on SW_B and you end up having untagged VLAN 99. Both of these are tasks they did not ask us to do.
Having untagged VLAN99 also conflicts with the question statement “For operational and security reasons .. Vlans .. should tagged when traversing the trunk link.” So they are making us tag VLAN 1 for operational and security reasons, why would they make us untag another VLAN?
i dont know why i have this message:
Switch(config-if-range)#no switchport access vlan 98
Switch(config-if-range)#sw
Switch(config-if-range)#switchport tru
Switch(config-if-range)#switchport trunk enc
Switch(config-if-range)#switchport trunk encapsula
Switch(config-if-range)#switchport trunk encapsulation dot1q
^
% Invalid input detected at ‘^’ marker.
Switch(config-if-range)#
Any one can help me please?
@MC
That just means that whatever you’re using, be it an emulated switch or real hardware, doesn’t support ISL encapsulation, so explicitly setting the encapsulation to 802.1Q is not an option because the switch supports 802.1Q alone anyway. You just have to issue the “switchport mode trunk” command.
Here is what you need dwz.win/qRc
Aren’t we going to name vlan’s 21-23 on Switch A too?
Passed today, 901 score! (41 questions and 3 labs)
Had a following labs: LACP with STP Sim, VTPv3 Sim, HSRP Sim, and all questions in the labs are the same as on certprepare and, believe me, all labs on certprepare have a right decision.
Other 41 questions: about 40% questions were new (I didn’t see them on certprepare), only one drag`n`drop (first question from Drag and Drop 2).
Hi everyone. Just a quick question, Do we have to configure anything on “interface port-channel 1” ???? it seems from the lab in packet tracer I got here that if I don’t configure “switchport trunk native vlan 99” on port channel 1 it wont allow me to have vlan 99 as my native vlan.
Dmytro how did yid you get the other new questions? Please advise.
@Anonymus, we need just configure adding physical interfaces to the port-channel, port-channel created automatically and it will have the config which we make on physical interfaces.
About native vlan: yes your are right, vlan 99 aren’t allow to the trunk and it’s normal for this topology, that is mean that untagged traffic will be dropped by switch.
@AAA I didn’t know about new questions and I didn’t see them earlier but I decided them on exam.
Does VLAN 1 ever need to be brought up on Sw-A or is it ment to be left “shutdown”? I noticed that on switch B we assign an IP address to VLAN 1, but never bring it up on switch A?
When I ping to 192.168.1.1 from SwB to SwA I get 120% and 140% why I am not getting 100%
and what does these numbers means (120% -140%) is this right or I am doing something wrong
can any one explain why the link between switch A and the Router is not trunked? please????
Do I need to configure this on the port-channel of sw_A and B??, cause configuring only this on the physical interface wont be inherited by the portchannel.
Sw_A(config)#inter port-channel 1
Sw_A(config-if)#switchport mode trunk
Sw_A(config-if)#switchport trunk allowed 1,21-23
Sw_A(config-if)#switchport trunk native vlan 99
Thanks All.
Also, Do we need to save the configurations?.
Thanks ALL
This lab is still valid I got it Nov 22
Any idea why am I getting “A statement from 8 to 13 is not correct!” in this simulator?
I have configured it correctly but it’s not accepting my commands. Not sure if this is a bug or what. Please take a look:
SwitchA(config)#int range fa0/3 – 4
SwitchA(config-if-range)#no switchport mode access
SwitchA(config-if-range)#no switchport access vlan 98
SwitchA(config-if-range)#switchport trunk encapsulation dot1q –> this line is already added on the simulator
SwitchA(config-if-range)#switchport mode trunk. —–> this is the statement 8
SwitchA(config-if-range)#switchport trunk native vlan 99
SwitchA(config-if-range)#switchport trunk allowed vlan 1,21-23
SwitchA(config-if-range)#channel-group1 mode active
SwitchA(config-if-range)#channel-protocol lacp
SwitchA(config-if-range)#no shutdown
Please help. Thank you always
please note that there is no period (.) after the word trunk.
i have configured it as switchport mode trunk but still not accepting in this sim
same with switch B. I’m also getting an error on setting the interface to trunkmode for interface fa0/3 – 4.. will check again tomorrow if this is a bug or what.
you are sure that the command int range fa0/3 – 4 its work because its didn’t work with me at the last time in the exam … i need to know this lab didn’t had any new command ?????
reham
int range fa0/3 – 4 surely works. it is the correct command even in the live environment.
Hi,
Does anyone know if 143Q is still valid?
I have just passed the test, this lab was there, exactly the same, HSRP and vtpv3 sim were there also.
I have got around 8 new questions in the exam.
@Anonymous i was afraid to have the exam as i saw here some one mentioned the Q had change 40% of it, so as your feedback that is okay to go and the exam will be almost the same?
Get it here” my name is the download link. Just put an “i” in tbe beginning
is ping to 192.168.1.1 rom switchb suppose to work?