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 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 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。