华为ensp，实现内网主机通过DHCP获取IP地址

方案

步骤

第一步：接入层交换机的基础配置：

SW1的配置：

vlan batch 10 20 30 40
int g0/0/1
port link-type access
port default vlan 10
int g0/0/2
port link-type access
port default vlan 20
int g0/0/12
port link-type trunk 
port trunk allow-pass vlan all

SW2的配置：
vlan batch 10 20 30 40
int g0/0/1
port link-type access
port default vlan 10
int g0/0/2
port link-type access
port default vlan 30
int g0/0/12
port link-type trunk 
port trunk allow-pass vlan all

SW3的配置：
vlan batch 10 20 30 40
int g0/0/1
port link-type access
port default vlan 20
int g0/0/2
port link-type access
port default vlan 40
int g0/0/12
port link-type trunk 
port trunk allow-pass vlan all