1- Configure interfaces in order be part of a channel group:

switch# configure terminal

switch(config)# interface fastethernet 0/1-2

switch(config-if)# channel-group 5 mode active

switch(config-if)# no shudown

Interface Gi0/1 & Gi0/2 will join interface port-channel 5 with LACP as negociation protocol.

2- Configure interface port-channel :

switch# configure terminal

switch(config)# interface port-channel 5

switch(config-if)# switchport mode trunk

switch(config-if)# switchport trunk allowed vlan 1-200

switch(config-if)# no shudown