SWITCH Training » LACP with STP Sim

Ensurepass

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.

Answer and Explanation:

Below is a good solution commented by Ruci. Please say thank to Ruci!

SW-A (close to router)
SW-A#configure terminal

SW-A(config)#spanning-tree vlan 11-13,21-23 root primary

SW-A(config)#vlan 21
SW-A(config-vlan)#name Marketing
SW-A(config-vlan)#exit

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

SW-A(config)#vlan 23
SW-A(config-vlan)#name Engineering
SW-A(config-vlan)#exit
SW-A(config)#interface range Fa0/3 – 4
SW-A(config-if-range)#no switchport mode access
SW-A(config-if-range)#no switchport access vlan 98 (These two commands must be deleted to form a trunking link)
SW-A(config-if-range)#switchport trunk encapsulation dot1q (cannot issued this command on this switch, but don’t worry coz I still got 100%)
SW-A(config-if-range)#switchport mode trunk
SW-A(config-if-range)#switchport trunk native vlan 99
SW-A(config-if-range)#switchport trunk allowed vlan 1,21-23
SW-A(config-if-range)#channel-group 1 mode active
SW-A(config-if-range)#channel-protocol lacp
SW-A(config-if-range)#no shutdown
SW-A(config-if-range)#end

——————————————————————————————–

SW-B (far from router)
SW-B#configure terminal

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

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-range)#switchport trunk encapsulation dot1q (yes I can issued this command on this switch)
SW-B(config-if-range)#switchport mode trunk
SW-B(config-if-range)#switchport trunk native vlan 99
SW-B(config-if-range)#switchport trunk allowed vlan 1,21-23
SW-B(config-if-range)#channel-group 1 mode passive //mode passive because “SwitchA controlling activation”
SW-B(config-if-range)#channel-protocol lacp
SW-B(config-if-range)#no shutdown
SW-B(config-if-range)#end

———————————————————

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 – x
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. 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 mode trunk
SW-A(config-if)#switchport trunk native vlan 99
—————————————
SW-B(config)#interface range Fa0/3 – 4
SW-B(config-if)#switchport trunk encapsulation dot1q (yes I can issued this command on this switch)
SW-B(config-if)#switchport mode trunk
SW-B(config-if)#switchport trunk native vlan 99
– 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. SW-A(config)#interface range Fa0/3 – 4
SW-A(config-if)#channel-group 1 mode active
SW-A(config-if)#channel-protocol lacp
SW-A(config-if)#no shutdown
—————————————
SW-B(config)#interface range Fa0/3 – 4
SW-B(config-if)#channel-group 1 mode passive
SW-B(config-if)#channel-protocol lacp
SW-B(config-if)#no shutdown
—————————————
Maybe the interface Port-channel 1 was configured on both switches so we don’t configure it here. If not we have to configure them with “interface port-channel 1″ command. Also you have to turn them up.
– 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)#switchport trunk allowed vlan 1,21-23
—————————————
SW-B(config)#interface range Fa0/3 – 4
SW-B(config-if)#switchport trunk allowed vlan 1,21-23

 

You may have to configure Interface Port-Channel on both switches. Check the configuration first, if it does not exist, use these commands:

Interface port-channel1
switchport mode trunk
switchport trunk native vlan 99 //this command will prevent the “Native VLAN mismatched” error on both switches
switchport trunk allowed vlan 1,21-23,99

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 have 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.

We hope with this information our candidates can find the best solution in the exam. If you learn anything new about this sim please share with us!

Other lab-sims in this site:

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