SVI：众所周知交换机是没有ip地址的，如果要配置的话一般需要本地console连接设置，这样在后期运维过程中不得不总是要跑到现场调试，SVI配置就是将交换机的一个vlan口，设置ip地址在配合Telnet远程登录权限，这样后期运维人员就可以远程通过ip地址直接Telnet登录到交换机内部进配置。
LSW1:
[LSW1]valn 10 20
[LSW1]int vlanif 10 创建交换机虚拟接口vlanif 10 (SVI)
[LSW1-Vlanif10]ip add 192.168.10.1 24 配置ip地址作为vlan10网关
[LSW1]int vlanif 20
[LSW1-Vlanif20]ip add 192.168.20.1 24 配置ip地址作为vlan20网关
注意：可以将三层交换机抽象成一台路由器，vlanif接口就是路由器的接口。
二层SVI
sw2:
[LSW1]vlan batch 10 30
[LSW1]interface Ethernet0/0/1
port link-type trunk
port trunk allow-pass vlan 2 to 4094
#
interface Ethernet0/0/2
port link-type access
port default vlan 10
#
interface Ethernet0/0/3
port link-type access
port default vlan 30
sw3:
vlan 20
interface Ethernet0/0/1
port link-type trunk
port trunk allow-pass vlan 2 to 4094
#
interface Ethernet0/0/2
port link-type access
port default vlan 20
sw1:
vlan batch 10 20 30
interface Vlanif10
ip address 192.168.10.1 255.255.255.0
#
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 GigabitEthernet0/0/1
port link-type trunk
port trunk allow-pass vlan all
#
interface GigabitEthernet0/0/2 port link-type trunk
port trunk allow-pass vlan all