核心交换机：
switchleft#show running-config
Building configuration...

Current configuration : 1826 bytes
!
version 16.3.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname switchleft
!
no ip cef
ip routing
!
no ipv6 cef
!

spanning-tree mode pvst
!
!

interface Port-channel30
no switchport
ip address 172.16.1.1 255.255.255.0
!
interface GigabitEthernet1/0/1
switchport access vlan 200
switchport mode access
switchport nonegotiate
!
interface GigabitEthernet1/0/2
no switchport
no ip address
duplex auto
speed auto
channel-group 30 mode active
!
interface GigabitEthernet1/0/3
no switchport
no ip address
duplex auto
speed auto
channel-group 30 mode active
!
!
interface Vlan1
no ip address
shutdown
!
interface Vlan200
mac-address 0005.5ed6.ad01
ip address 192.168.200.1 255.255.255.0
!
interface Vlan210
mac-address 0005.5ed6.ad02
no ip address
!
ip classless
ip route 192.168.0.0 255.255.0.0 192.168.200.2
!
ip flow-export version 9
!
!

line con 0
!
line aux 0
!
line vty 0 4
login
!

end

汇聚交换机：
leftl2#show running-config
Building configuration...

Current configuration : 2810 bytes
!
version 12.2(37)SE1
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname leftl2
!

!
ip routing
!

spanning-tree mode pvst
spanning-tree vlan 20 priority 8192
spanning-tree vlan 21 priority 24576
!
interface Loopback21
ip address 172.16.100.21 255.255.255.0
!
interface Port-channel3
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface Port-channel5
switchport access vlan 100
switchport mode access
switchport nonegotiate
!
interface FastEthernet0/1
switchport trunk encapsulation dot1q
switchport mode trunk
channel-protocol lacp
channel-group 3 mode active
!
interface FastEthernet0/2
switchport trunk encapsulation dot1q
switchport mode trunk
channel-protocol lacp
channel-group 3 mode active
!
interface FastEthernet0/3
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/4
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/5
switchport access vlan 200
switchport mode access
switchport nonegotiate
!
interface FastEthernet0/6
switchport mode access
switchport nonegotiate
shutdown
!

!
interface GigabitEthernet0/1
switchport access vlan 100
switchport mode access
switchport nonegotiate
channel-group 5 mode on
!
interface GigabitEthernet0/2
switchport access vlan 100
switchport mode access
switchport nonegotiate
channel-group 5 mode on
!
interface Vlan1
no ip address
shutdown
!
interface Vlan20
mac-address 00d0.bcc5.2101
ip address 192.168.20.252 255.255.255.0
ip helper-address 192.168.200.253
standby 20 ip 192.168.20.254
standby 20 priority 150
standby 20 preempt
!
interface Vlan21
mac-address 00d0.bcc5.2102
ip address 192.168.21.252 255.255.255.0
ip helper-address 192.168.200.253
standby 21 ip 192.168.21.254
standby 21 preempt
!
interface Vlan50
mac-address 00d0.bcc5.2103
ip address 192.168.50.252 255.255.255.0
ip helper-address 192.168.200.253
standby 50 ip 192.168.50.254
!
interface Vlan200
mac-address 00d0.bcc5.2104
ip address 192.168.200.2 255.255.255.0
!
ip classless
ip route 0.0.0.0 0.0.0.0 192.168.200.1
!
ip flow-export version 9
!
!
line con 0
!
line aux 0
!
line vty 0 4
login
!
end