Task 1: Configure an LACP EtherChannel with the number 1 between SW1 and SW2 using FastEthernet0/1 and FastEthernet0/2 on both switches. The LACP mode must match on both ends.

LACP uses two modes, 'active' and 'passive' mode. In active mode, a switch actively initiates and negotiates the formation of an EtherChannel by sending LACP packets to its counterpart. In passive mode, a switch listens for LACP packets but does not actively initiate the negotiation. At least one end of the link must be configured in active mode for LACP to form an EtherChannel.

Active + Passive or Active + Active combinations will successfully form an EtherChannel. As the LACP mode must match on both ends, Both the switches must be configured in active mode. If both devices are in passive mode, EtherChannel will not form because neither initiates the negotiation.

On SW1:

SW1#configure terminal
SW1(config)#interface range f0/1-2
SW1(config-if-range)#channel-group 1 mode active
SW1(config-if-range)#exit

On SW2:

SW2#configure terminal
SW2(config)#interface range f0/1-2
SW2(config-if-range)#channel-group 1 mode active
SW2(config-if-range)#exit

The interface range command allows us to configure the interfaces collectively which can save a lot of time. channel-group 1 mode active enables LACP in active mode on interfaces FastEthernet0/1 and FastEthernet0/2 and assigns them to EtherChannel group 1.

Task 2: Set the EtherChannel to operate as a trunk link using IEEE 802.1Q tagging.

To configure the etherchannel we created, we need to use the interface port-channel 1 command. Remember that etherchannel in Cisco IOS is sometimes also called channel-group and port-channel.

On SW1:

SW1(config)#interface port-channel 1
SW1(config-if)#switchport trunk encapsulation dot1q
SW1(config-if)#switchport mode trunk
SW1(config-if)#end

On SW2:

SW2(config)#interface port-channel 1
SW2(config-if)#switchport trunk encapsulation dot1q
SW2(config-if)#switchport mode trunk
SW2(config-if)#end

switchport trunk encapsulation dot1q specifies the use of IEEE 802.1Q for VLAN tagging. switchport mode trunk configures the EtherChannel as a trunk link.

Task 3: Assign VLAN "Control" as the native VLAN for the trunk link.

First use the show vlan brief command on both switches to find out the "Control" VLAN.

On SW1:

SW1#show vlan brief

VLAN Name                             Status    Ports

---- -------------------------------- --------- -------------------------------

--output omitted--

99   Control                          active    

On SW2:

SW2#show vlan brief

VLAN Name                             Status    Ports

---- -------------------------------- --------- -------------------------------

--output omitted--

99   Control                          active    

The output shows that "Control" VLAN is VLAN 99.

On SW1:

SW1#configure terminal
SW1(config)#interface port-channel 1
SW1(config-if)#switchport trunk native vlan 99
SW1(config-if)#end

On SW2:

SW2#configure terminal
SW2(config)#interface port-channel 1
SW2(config-if)#switchport trunk native vlan 99
SW2(config-if)#end

Verifcation:

Use the show etherchannel summary command on both switches to verify.

On SW1:

SW1#show etherchannel summary

--output omitted--

Group  Port-channel  Protocol    Ports

------+-------------+-----------+----------------------------------------------

1      Po1(SU)           LACP   Fa0/1(P) Fa0/2(P)

On SW2:

SW1#show etherchannel summary

--output omitted--

Group  Port-channel  Protocol    Ports

------+-------------+-----------+----------------------------------------------

1      Po1(SU)           LACP   Fa0/1(P) Fa0/2(P)

"SU" means that etherchannel formation was successful.

Now  save the configuration.

SW1#write memory

SW2#write memory