一、实验拓扑：

二、命令部署：1、基本命令：Server(config)#int f1/0Server(config-if)#no shutdown Server(config-if)#no switchport Server(config-if)#ip add 172.168.24.1 255.255.255.0

Server(config)#ip dhcp pool vlan10

Server(dhcp-config)#network 192.168.10.0 255.255.255.0Server(dhcp-config)#default-router 192.168.10.254Server(dhcp-config)#dns-server 8.8.8.8Server(dhcp-config)#lease 15

Server(config)#ip dhcp pool vlan20

Server(dhcp-config)#network 192.168.20.0 255.255.255.0Server(dhcp-config)#default-router 192.168.20.254Server(dhcp-config)#dns-server 8.8.8.8Server(dhcp-config)#lease 30

Server(config)#ip dhcp excluded-address 192.168.10.254

Server(config)#ip dhcp excluded-address 192.168.20.254

Server(config)#ip routing

Server(config)#router ospf 100Server(config-router)#network 172.168.24.0 0.0.0.255 area 0

SW1(config)#int f1/0

SW1(config-if)#no shutdown SW1(config-if)#no switchport SW1(config-if)#ip address 172.168.24.2 255.255.255.0

SW1(config)#int f1/1

SW1(config-if)#no shutdown SW1(config-if)#switchport trunk encapsulation dot1q SW1(config-if)#switchport mode trunk

SW1(config)#int vlan 10

SW1(config-if)#no shutdown SW1(config-if)#ip address 192.168.10.254 255.255.255.0SW1(config)#int vlan 20SW1(config-if)#no shutdown SW1(config-if)#ip address 192.168.20.254 255.255.255.0

SW1(config)#ip routing

SW1(config)#router ospf 100SW1(config-router)#network 172.168.24.0 0.0.0.255 area 0SW1(config-router)#network 192.168.10.0 0.0.0.255 area 0SW1(config-router)#network 192.168.20.0 0.0.0.255 area 0

SW2(config)#int f1/0

SW2(config-if)#no shutdown SW2(config-if)#switchport trunk encapsulation dot1q SW2(config-if)#switchport mode trunk

SW2(config)#int f1/1

SW2(config-if)#no shutdown SW2(config-if)#switchport mode access SW2(config-if)#switchport access vlan 10

SW2(config)#int f1/2

SW2(config-if)#no shutdown SW2(config-if)#switchport mode access SW2(config-if)#switchport access vlan 20

SW2(vlan)#vlan 10

VLAN 10 added:Name: VLAN0010SW2(vlan)#vlan 20VLAN 20 added:Name: VLAN0020

SW2(config)#no ip routing

PC1(config)#int f0/0

PC1(config-if)#no shutdown PC1(config-if)#ip address dhcpPC1(config)#no ip routingPC1(config)#ip default-gateway 192.168.10.254

PC2(config)#int f0/0

PC2(config-if)#no shutdown PC2(config-if)#ip address dhcpPC2(config)#no ip routingPC2(config)#ip default-gateway 192.168.20.254

2、重点命令：

SW1(config)#int vlan 10SW1(config-if)#ip helper-address 172.168.24.1

SW1(config)#int vlan 20

SW1(config-if)#ip helper-address 172.168.24.1

三、验证：

（1）交换机SW2和三层交换机SW1抓包VLAN20发出的DHCP DiscoverVLAN10发出的DHCP Discover（2）Server端和三层交换机SW1之间抓包GNS3-0.8.6

GNS3：IOU

结论：必须要用IOU做才有效果，其它模拟命令可以敲，但是都没有效果的。