interface FastEthernet0/1
switchport mode trunk
!-- Configured port to be in trunking mode.
channel-group 1 mode on
!-- Assigned port to port channel 1.
!-- 2950 switches only support 802.1q encapsulation, which is the configured automatically
!-- when trunking is enabled on the interface by issuing the switchport mode trunk command.
!-- Note: The channel-group command is introduced in IOS 12.1. IOS 12.0 has the port group command
!-- to configure channeling.
 
!
interface FastEthernet0/2
switchport mode trunk
channel-group 1 mode on
!-- Assigned port to port channel 1.
!
interface FastEthernet0/3
switchport mode trunk
channel-group 1 mode on
!-- Assigned port to port channel 1.
!
interface FastEthernet0/4
switchport mode trunk
channel-group 1 mode on
!-- Assigned port to port channel 1.
补充一下
interface Port-channel1
switchport mode trunk