一：实验环境
1.1： 华为ensp软件
1.2： PC机和路由器及交换机
初始化状态的PC机和初始化状态的路由器，交换机
二：实验过程
2.1：配置设备
在ensp中，将PC机和路由器及交换机按图示做成拓扑图。
2.2 配置SW1交换机
1[SW1]vlan batch 10 20 2[SW1]int e0/0/1 3[SW1-Ethernet0/0/1]p l a 4[SW1-Ethernet0/0/1]p d v 10 5[SW1-Ethernet0/0/1]un sh 6[SW1-Ethernet0/0/1]int e0/0/2 7[SW1-Ethernet0/0/2]p l a 8[SW1-Ethernet0/0/2]p d v 20 9[SW1-Ethernet0/0/2]un sh 10[SW1-Ethernet0/0/2]int e0/0/3 11[SW1-Ethernet0/0/3]p l a 12[SW1-Ethernet0/0/3]p d v 10 13[SW1-Ethernet0/0/3]un sh 14[SW1-Ethernet0/0/4]int e0/0/4 15[SW1-Ethernet0/0/4]p l a 16[SW1-Ethernet0/0/4]p d v 20 17[SW1-Ethernet0/0/4]un sh 18[SW1-Ethernet0/0/4]int g0/0/1 19[SW1-GigabitEthernet0/0/1]p l t 20[SW1-GigabitEthernet0/0/1]p t a v a 21[SW1-GigabitEthernet0/0/1]un sh 22[SW1]dis int b 23Ethernet0/0/1 up up 0% 0% 0 0 24Ethernet0/0/2 up up 0% 0% 0 0 25Ethernet0/0/3 up up 0% 0% 0 0 26Ethernet0/0/4 up up 0% 0% 27[SW1]dis cu 28interface Ethernet0/0/1 29 port link-type access 30 port default vlan 10 31interface Ethernet0/0/2 32 port link-type access 33 port default vlan 20 34interface Ethernet0/0/3 35 port link-type access 36 port default vlan 10 37interface Ethernet0/0/4 38 port link-type access 39 port default vlan 20 40interface GigabitEthernet0/0/1 41 port link-type trunk 42 port trunk allow-pass vlan 2 to 4094
2.3 配置R1路由器
先配置单臂路由
1interface GigabitEthernet0/0/0 2 ip address 12.0.0.1 255.255.255.0 3[R1]int g0/0/1.10 4[R1-GigabitEthernet0/0/1.10]ip add 192.168.10.1 24 5[R1-GigabitEthernet0/0/1.10]d t v 10 6[R1-GigabitEthernet0/0/1.10]a b e 7[R1-GigabitEthernet0/0/1.10]un sh 8[R1]int g0/0/1.20 9[R1-GigabitEthernet0/0/1.20]ip add 192.168.20.1 24 10[R1-GigabitEthernet0/0/1.20]dot1q termination vid 20 11[R1-GigabitEthernet0/0/1.20]arp broadcast enable 12[R1-GigabitEthernet0/0/1.20]un sh
再配置DNS
1[R1]int g0/0/1.10 2[R1-GigabitEthernet0/0/1.10]dhcp select interface 3[R1-GigabitEthernet0/0/1.10]dhcp server dns-list 2.2.2.2 8.8.8.8 4[R1-GigabitEthernet0/0/1.10]int g0/0/1.20 5[R1-GigabitEthernet0/0/1.20]dhcp select interface 6[R1-GigabitEthernet0/0/1.20]dhcp server dns-list 2.2.2.2 8.8.8.8 7[R1-GigabitEthernet0/0/1.20]dis this 8interface GigabitEthernet0/0/1.20 9 dot1q termination vid 20 10 ip address 192.168.20.1 255.255.255.0 11 arp broadcast enable 12 dhcp select interface 13 dhcp server dns-list 2.2.2.2 8.8.8.8 14[R1-GigabitEthernet0/0/1.20]int g0/0/1.10 15[R1-GigabitEthernet0/0/1.10]dis this 16interface GigabitEthernet0/0/1.10 17 dot1q termination vid 10 18 ip address 192.168.10.1 255.255.255.0 19 arp broadcast enable 20 dhcp select interface 21 dhcp server dns-list 2.2.2.2 8.8.8.8
配置路由
[R1]ip route-static 0.0.0.0 0.0.0.0 12.0.0.2
2.4 配置R2路由器
先配置接口
1[R2]int g0/0/0 2[R2-GigabitEthernet0/0/0]ip add 12.0.0.2 24 3[R2-GigabitEthernet0/0/0]un sh 4[R2-GigabitEthernet0/0/0]int g0/0/1 5[R2-GigabitEthernet0/0/1]ip add 15.0.0.1 24 6[R2-GigabitEthernet0/0/1]un sh
再配置DHCP
1[R2]dhcp enable 2[R2-GigabitEthernet0/0/1]dhcp select global 3[R2-GigabitEthernet0/0/1]q 4[R2]ip pool DHCP15 5[R2-ip-pool-DHCP15]network 15.0.0.0 mask 24 6[R2-ip-pool-DHCP15]gateway-list 15.0.0.1 7[R2-ip-pool-DHCP15]dns-list 8.8.8.8 2.2.2.2 8[R2-ip-pool-DHCP15]dis this 9ip pool DHCP15 10 gateway-list 15.0.0.1 11 network 15.0.0.0 mask 255.255.255.0 12 dns-list 8.8.8.8 2.2.2.2 13[R2]ip route-static 192.168.10.0 24 12.0.0.1 14[R2]ip route-static 192.168.20.0 24 12.0.0.1
2.5 PC端测试
把其余PC均设置DHCP 再应用并查看其他地址
Ipconfig /renew 重新获取ip地址
Ipconfig /release 释放IP地址
再用其他PC ping 192.168.10.254，都能ping通
2.4 抓包研究DHCP报文
