1.通过搭建的拓扑图来实现PC的IP地址自动获取
2.配置思路：
⑴首先将PC机调到DHCP自动获取状态；
⑵创建相应的VLAN，将VLAN放入对应的端口；
<Huawei>system-view
[SW2]vlan batch 10 20 30
[SW2]interface Eth0/0/2
[SW2-Ethernet0/0/2]port link-type access
[SW2-Ethernet0/0/2]port default vlan 10
[SW2]interface Eth0/0/3
[SW2-Ethernet0/0/3]port link-type access
[SW2-Ethernet0/0/3]port default vlan 20
[SW2]interface Eth0/0/1
[SW2-Ethernet0/0/1]port link-type trunk
[SW2-Ethernet0/0/1]port trunk allow-pass vlan all
<Huawei>system-view
[SW3]vlan batch 10 20 30
[SW3]interface Eth0/0/2
[SW3-Ethernet0/0/2]port link-type access
[SW3-Ethernet0/0/2]port default vlan 30
[SW3]interface Eth0/0/1
[SW3-Ethernet0/0/1]port link-type trunk
[SW3-Ethernet0/0/1]port trunk allow-pass vlan all
⑶在三层交换机上创建DHCP地址池，并开启；
<Huawei>system-view
[SW1]vlan batch 10 20 30
[SW1]interface GigabitEthernet 0/0/1
[SW1-GigabitEthernet0/0/1]port link-type trunk
[SW1-GigabitEthernet0/0/1]port trunk allow-pass vlan all
[SW1-GigabitEthernet0/0/1]int g0/0/2
[SW1-GigabitEthernet0/0/2]port link-type trunk
[SW1-GigabitEthernet0/0/2]port trunk allow-pass vlan all
[SW1]interface Vlanif 10
[SW1-Vlanif10]ip address 192.168.1.254 24
[SW1-Vlanif10]int vl20
[SW1-Vlanif20]ip address 192.168.2.254 24
[SW1-Vlanif20]int vl30
[SW1-Vlanif30]ip address 192.168.3.254 24
[SW1]dhcp enable
[SW1]ip pool vlan10
[SW1-ip-pool-vlan10]network 192.168.1.0 mask 24
[SW1-ip-pool-vlan10]gateway-list 192.168.1.254
[SW1-ip-pool-vlan10]dns-list 8.8.8.8
[SW1]ip pool vlan20
[SW1-ip-pool-vlan20]network 192.168.2.0 mask 24
[SW1-ip-pool-vlan20]gateway-list 192.168.2.254
[SW1-ip-pool-vlan20]dns-list 8.8.8.8
[SW1]ip pool vlan30
[SW1-ip-pool-vlan30]network 192.168.3.0 mask 24
[SW1-ip-pool-vlan30]gateway-list 192.168.3.254
[SW1-ip-pool-vlan30]dns-list 8.8.8.8
[SW1]interface Vlanif 10
[SW1-Vlanif10]dhcp select global
[SW1-Vlanif10]int vl20
[SW1-Vlanif20]dhcp select global
[SW1-Vlanif20]int vl30
[SW1-Vlanif30]dhcp select global
⑷ 验证；注意：华为获取的IP地址是从254往下开始分配的，思科是从1往上开始分配的；
PC1：
PC2：
PC3：