下面是局域网的核心交换机(三层交换)和二层交换之间的端口聚合的操作实例:


 2950
  Switch>en
  Switch#conf t
  Enter configuration commands, one per line. End with CNTL/Z.
  Switch(config)#int f0/1
  Switch(config-if)#channel-group 1 mode on
  %LINK-5-CHANGED: Interface Port-channel 1, changed state to up
  %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel 1, changed state to upSwitch(config-if)#int f0/2
  Switch(config-if)#channel-group 1 mode on
  3560
  Switch(config)#int port-channel 1
  Switch(config-if)#exit
  Switch(config)#ip routing(默认已经启用了路由功能)
  Switch(config)#int port-channel 1
  Switch(config-if)#no switchport
  Switch(config-if)#ip add 1.1.1.1 255.0.0.0
  Switch(config-if)#no shut
  Switch(config-if)#exit
  Switch(config)#int f0/1
  Switch(config-if)#no switchport
  %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
  %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to upSwitch(config-if)#
  Switch(config-if)#no ip add
  Switch(config-if)#channel-group 1 mode ?
  active Enable LACP unconditionally
  auto Enable PAgP only if a PAgP device is detected
  desirable Enable PAgP unconditionally
  on Enable Etherchannel only
  passive Enable LACP only if a LACP device is detected
  Switch(config-if)#channel-group 1 mode on
  %LINK-5-CHANGED: Interface Port-channel 1, changed state to up
  %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel 1, changed state to upSwitch(config-if)#
  Switch(config-if)#int f0/2
  Switch(config-if)#no switchport
  %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/2, changed state to down
  %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/2, changed state to upSwitch(config-if)#no ip add
  Switch(config-if)#no ip address
  Switch(config-if)#channel-group 1 mode on
  Switch(config-if)#exit
  Switch(config)#int f0/3
  Switch(config-if)#no switchport
  %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/3, changed state to down
  %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/3, changed state to upSwitch(config-if)#ip add 2.2.2.1 255.0.0.0
  Switch(config-if)#no shut
  端口聚合可使流量在多条物理链路上负载均衡,同时也起到了链路的备份作用。但是在某些设备里,应注意聚合链路两端接口的速率,工作模式,例如在快以中,可将各个端口设置为speed 100,duplex full。