An example of port-channel with 3 switches.
Partial config of switch SW1:
interface Port-channel1 switchport trunk encapsulation dot1q switchport mode trunk ! interface Port-channel2 switchport trunk encapsulation dot1q switchport mode trunk ! interface GigabitEthernet0/0 switchport trunk encapsulation dot1q switchport mode trunk media-type rj45 negotiation auto channel-group 1 mode active ! interface GigabitEthernet0/1 switchport trunk encapsulation dot1q switchport mode trunk media-type rj45 negotiation auto channel-group 1 mode active ! interface GigabitEthernet0/2 switchport trunk encapsulation dot1q switchport mode trunk media-type rj45 negotiation auto channel-group 2 mode active ! interface GigabitEthernet0/3 switchport trunk encapsulation dot1q switchport mode trunk media-type rj45 negotiation auto channel-group 2 mode active
Creating port-channel step by step
Step 1: create interface port-channel
SW1#configure terminal SW1(config)#interface port-channel 4 SW1(config-if)#exit
Step 2: show running-config
[partial config]
SW1#show running-config ! interface Port-channel4 !
Step 3: make interfaces member of channel-group
In this example, 2 interfaces are added to channel-group 4.
SW1#configure terminal SW1(config)#interface gigabitEthernet 1/0 SW1(config-if)#channel-group 4 mode active SW1(config-if)#exit SW1(config)#interface gigabitEthernet 1/1 SW1(config-if)#channel-group 4 mode active SW1(config-if)#end
Step 4: show running-config
SW1#show running-config [partial config] ! interface Port-channel4 ! interface GigabitEthernet1/0 media-type rj45 negotiation auto channel-group 4 mode active ! interface GigabitEthernet1/1 media-type rj45 negotiation auto channel-group 4 mode active !
Step 5: configure port-channel
Configure the port-channel with “switchport trunk encapsulation dot1q” and “switchport mode trunk”.
SW1#configure terminal SW1(config)#interface port-channel 4 SW1(config-if)#switchport trunk encapsulation dot1q SW1(config-if)#switchport mode trunk
Step 6: show running-config
SW1#show running-config [partial config] ! interface Port-channel4 switchport trunk encapsulation dot1q switchport mode trunk ! interface GigabitEthernet1/0 switchport trunk encapsulation dot1q switchport mode trunk media-type rj45 negotiation auto channel-group 4 mode active ! interface GigabitEthernet1/1 switchport trunk encapsulation dot1q switchport mode trunk media-type rj45 negotiation auto channel-group 4 mode active
The interfaces, which are member of channel-group 4, also receive the configuration as configured on port-channel4.