交換機A的配置：
vlan batch 20 30
#
interface Vlanif1
ip address 192.168.1.1 255.255.255.0
#
interface Vlanif20
ip address 192.168.20.1 255.255.255.0
#
interface Vlanif30
ip address 192.168.30.1 255.255.255.0
interface Ethernet0/0/1
port link-type access
port default vlan 20
#
interface Ethernet0/0/2
port link-type access
port default vlan 30
ip route-static 192.168.20.0 255.255.255.0 192.168.1.2
ip route-static 192.168.30.0 255.255.255.0 192.168.1.2
交換機的B配置
vlan batch 40
interface Vlanif1
ip address 192.168.1.2 255.255.255.0
#
interface Vlanif40
ip address 192.168.40.1 255.255.255.0
ip route-static 192.168.40.0 255.255.255.0 192.168.1.1
在兩個交換配之間端口做trunk配置，並允許所有的vlan通過