Cisco交换机链路聚合

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 com被过滤广告mands, 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。