cisco dhcp 单臂路由

说明：

pc4 pc5 位于vlan 10 从路由器dhcp获取的IP段 192.168.10.0/24

pc6 pc7位于vlan 20 从路由器dhcp获取的IP段 192.168.20.0/24

vlan 10内所有的机器的网关为192.168.10.254

vlan 20内所有的机器的网关为192.168.20.254
不同vlan 可以进行通讯

1.配置交换机吧
接口划分至相应的vlan

Switch#show  vlan  briefVLAN Name                             Status    Ports---- -------------------------------- --------- -------------------------------1    default                          active    Fa0/6, Fa0/7, Fa0/8, Fa0/9Fa0/10, Fa0/11, Fa0/12, Fa0/13Fa0/14, Fa0/15, Fa0/16, Fa0/17Fa0/18, Fa0/19, Fa0/20, Fa0/21Fa0/22, Fa0/23, Fa0/2410   v10                              active    Fa0/2, Fa0/320   v20                              active    Fa0/4, Fa0/51002 fddi-default                     active1003 token-ring-default               active1004 fddinet-default                  active1005 trnet-default                    activeSwitch#

2.配置vlan 的

SW1(config)#interface vlan 10   SW1(config-if)#ip helper-address 192.168.10.254 #单臂路由的子接口 vlan10的SW1(config)#interface vlan 20   SW1(config-if)#ip helper-address 192.168.20.254 #单臂路由的子接口 vlan20的

3.配置交换机的上行接口为trunk

Switch(config)#interface  fastEthernet 0/1Switch(config-if)#swSwitch(config-if)#switchport  mode  trunk

4.配置路由器单臂路由（路由器和交换机链接的端口是fa0/0 口）

Router(config)#interface fastEthernet 0/0.10Router(config-subif)#encapsulation  dot1Q  10Router(config-subif)#ip addRouter(config-subif)#ip address  192.168.10.254  255.255.255.0Router(config)#interface fastEthernet 0/0.20Router(config-subif)#encapsulation  dot1Q  20Router(config-subif)#ip addRouter(config-subif)#ip address  192.168.20.254  255.255.255.0

5.配置dhcp

Router(config)#ip  dhcp pool vlan10  #vlan10只是名字Router(dhcp-config)#network 192.168.10.0  255.255.255.0Router(dhcp-config)#dns-server 223.5.5.5Router(dhcp-config)#default-router  192.168.10.254Router(dhcp-config)#exitRouter(config)#ip dhcp  excluded-address  192.168.10.254Router(config)#ip  dhcp pool vlan20  #vlan20只是名字Router(dhcp-config)#network 192.168.20.0  255.255.255.0Router(dhcp-config)#dns-server 223.5.5.5Router(dhcp-config)#default-router  192.168.20.254Router(dhcp-config)#exitRouter(config)#ip dhcp  excluded-address  192.168.20.254

最终测试：不同vlan获取了不同的Ip 不同vlan可以通讯 OK