1. 配置DHCP中继
   [LSW2]vlan batch 10 20
   [LSW2-GigabitEthernet0/0/1]port link-type hybrid
   [LSW2-GigabitEthernet0/0/1]port hybrid pvid vlan 10
   [LSW2-GigabitEthernet0/0/1]port hybrid untagged vlan 10
   [LSW2-GigabitEthernet0/0/2]port link-type hybrid
   [LSW2-GigabitEthernet0/0/2]port hybrid pvid vlan 10
   [LSW2-GigabitEthernet0/0/2]port hybrid untagged vlan 10
   [LSW2-GigabitEthernet0/0/3]port link-type hybrid
   [LSW2-GigabitEthernet0/0/3]port hybrid pvid vlan 20
   [LSW2-GigabitEthernet0/0/3]port hybrid untagged vlan 20
   [LSW2]int Vlanif 20
   [LSW2-Vlanif20]ip add 10.1.2.2 24
   [LSW2]dhcp enable
   [LSW2]int Vlanif 10
   [LSW2-Vlanif10]ip add 10.1.1.1 24
   [LSW2-Vlanif10]dhcp select relay
   [LSW2-Vlanif10]dhcp relay server-ip 10.1.2.1
2. 在LSW2上配置缺省路由
   [LSW2]ip route-static 0.0.0.0 0.0.0.0 10.1.2.1
3. 在LSW1上配置基于全局地址池的DHCP服务器功能
   [LSW1]dhcp enable
   [LSW1]vlan 20
   [LSW1-GigabitEthernet0/0/1]port link-type hybrid
   [LSW1-GigabitEthernet0/0/1]port hybrid pvid vlan 20
   [LSW1-GigabitEthernet0/0/1]port hybrid untagged vlan 20
   [LSW1-Vlanif20]ip add 10.1.2.1 24
   [LSW1-Vlanif20]dhcp select global
   [LSW1]ip pool pool1 //创建地址池并配置相关属性
   [LSW1-ip-pool-pool1]network 10.1.1.0 mask 24
   [LSW1-ip-pool-pool1]gateway-list 10.1.1.1
   [LSW1-ip-pool-pool1]option121 ip-address 10.1.2.0 24 10.1.2.1
4. 在LSW1上配置静态路由
   [LSW1]ip route-static 10.1.1.0 24 10.1.2.2
5. PC选择以DHCP方式获取IP地址
6. 验证配置