Cisco-DHCP中继实验案例
Cisco-三层VLAN+DHCP实验案例
说明：某公司有三个部门，划分三个VLAN进行隔离，IP地址通过vlan40中的DHCP服务器进行下发，保证各个部门的主机获取到IP地址，通过三层交换机的路由访问外部网络。
IP地址规划表
| 设备 | 接口 | 地址 |
|---|---|---|
| Switch31 | VLAN 10 | 192.168.10.254/24 |
| Switch31 | VLAN 20 | 192.168.20.254/24 |
| Switch31 | VLAN 30 | 192.168.30.254/24 |
| Switch31 | VLAN 40 | 192.168.40.254/24 |
| Switch31 | FastEthernet0/4 | 200.100.10.1/30 |
| R1 | GigabitEthernet0/0 | 200.100.20.1/24 |
| R1 | GigabitEthernet0/1 | 200.100.10.2/30 |
| DHCP-Server | FastEthernet0 | 192.168.40.1/24 |
| PC0 | FastEthernet0 | 200.100.20.1/24 |
| PC1-3 | FastEthernet0 | DHCP获取 |
| PC4-6 | FastEthernet0 | DHCP获取 |
| PC7-9 | FastEthernet0 | DHCP获取 |
接口规划表
| 本端设备 | 接口 | 端口类型 | 对端设备 | 接口 |
|---|---|---|---|---|
| Switch31 | FastEthernet0/1 | Trunk | Switch0 | FastEthernet0/4 |
| Switch31 | FastEthernet0/2 | Trunk | Switch1 | FastEthernet0/4 |
| Switch31 | FastEthernet0/3 | Trunk | Switch2 | FastEthernet0/4 |
| Switch31 | FastEthernet0/4 | Access | DHCP-Server | FastEthernet0 |
| Switch31 | FastEthernet0/5 | R1 | GigabitEthernet0/1 | |
| R1 | GigabitEthernet0/0 | PC0 | FastEthernet0 | |
| Switch0 | FastEthernet0/1 | Access | PC1 | FastEthernet0 |
| Switch0 | FastEthernet0/2 | Access | PC2 | FastEthernet0 |
| Switch0 | FastEthernet0/3 | Access | PC3 | FastEthernet0 |
| Switch1 | FastEthernet0/1 | Access | PC4 | FastEthernet0 |
| Switch1 | FastEthernet0/1 | Access | PC5 | FastEthernet0 |
| Switch1 | FastEthernet0/1 | Access | PC6 | FastEthernet0 |
| Switch2 | FastEthernet0/1 | Access | PC7 | FastEthernet0 |
| Switch2 | FastEthernet0/1 | Access | PC8 | FastEthernet0 |
| Switch2 | FastEthernet0/1 | Access | PC9 | FastEthernet0 |
项目实施
一、配置各接口所属VLAN和地址
#Switch31的配置
Switch31(config)#vlan 10
Switch31(config-vlan)#vlan 20
Switch31(config-vlan)#vlan 30
!
Switch31(config)interface FastEthernet0/1
Switch31(config-if)switchport mode trunk
Switch31(config-if)#switchport trunk allowed vlan 10
!
Switch31(config)interface FastEthernet0/2
Switch31(config-if)switchport mode trunk
Switch31(config-if)#switchport trunk allowed vlan 20
!
Switch31(config)interface FastEthernet0/3
Switch31(config-if)switchport mode trunk
Switch31(config-if)#switchport trunk allowed vlan 30
!
Switch31(config)interface FastEthernet0/4
Switch31(config-if)#no switchport
Switch31(config-if)#ip address 200.100.10.1 255.255.255.0
!
Switch31(config)interface FastEthernet0/5
Switch31(config-if)switchport mode access
Switch31(config-if)#switchport access vlan 40
!
Switch31(config)#int vlan 10
Switch31(config-if)#ip address 192.168.10.254 255.255.255.0
!
Switch31(config)#int vlan 20
Switch31(config-if)#ip address 192.168.20.254 255.255.255.0
!
Switch31(config)#int vlan 30
Switch31(config-if)#ip address 192.168.30.254 255.255.255.0
!
Switch31(config)#int vlan 40
Switch31(config-if)#ip address 192.168.40.254 255.255.255.0
R1的配置
Router1(config)#interface GigabitEthernet0/0
Router1(config-if)#ip address 200.100.20.1 255.255.255.0
!
Router1(config)#interface GigabitEthernet0/1
Router1(config-if)#ip address 200.100.10.2 255.255.255.0
Switch1的配置
Switch0(config)#vlan 10
Switch0(config-vlan)#exit
!
Switch0(config)#interface FastEthernet0/4
Switch0(config-if)#switchport mode trunk
Switch0(config-if)#switchport trunk allowed vlan 10
!
Switch0(config)#interface range fa0/1 - fa0/3
Switch0(config-if-range)#switchport mode access
Switch0(config-if-range)#switchport access vlan 10
Switch2的配置
Switch0(config)#vlan 20
Switch0(config-vlan)#exit
!
Switch0(config)#interface FastEthernet0/4
Switch0(config-if)#switchport mode trunk
Switch0(config-if)#switchport trunk allowed vlan 20
!
Switch0(config)#interface range fa0/1 - fa0/3
Switch0(config-if-range)#switchport mode access
Switch0(config-if-range)#switchport access vlan 20
Switch3的配置
Switch0(config)#vlan 30
Switch0(config-vlan)#exit
!
Switch0(config)#interface FastEthernet0/4
Switch0(config-if)#switchport mode trunk
Switch0(config-if)#switchport trunk allowed vlan 30
!
Switch0(config)#interface range fa0/1 - fa0/3
Switch0(config-if-range)#switchport mode access
Switch0(config-if-range)#switchport access vlan 30
二、配置DHCP服务器
翻译乃个人理解，并非纯翻译！！！
三、配置DHCP中继
此拓扑中DHCP中继的作用是为了实现在不同子网中实现转发DHCP信息的功能。
#Switch31的配置
Switch31(config)#int vlan 10
Switch31(config-if)#ip address 192.168.10.254 255.255.255.0
Switch31(config-if)#ip helper-address 192.168.40.1
!
Switch31(config)#int vlan 20
Switch31(config-if)#ip address192.168.20.254 255.255.255.0
Switch31(config-if)#ip helper-address 192.168.40.1
!
Switch31(config)#int vlan 30
Switch31(config-if)#ip address 192.168.30.254 255.255.255.0
Switch31(config-if)#ip helper-address 192.168.40.1
四、配置路由实现内部网络访问外部网络
#Switch31的配置
Switch31(config)#ip route 0.0.0.0 0.0.0.0 200.100.10.2
R1的配置
Router1(config)#ip route 192.168.0.0 255.255.0.0 200.100.10.1
项目效果
VLAN 10内DHCP下发地址的效果
VLAN 20内地址下发的效果
VLAN 30内DHCP下发地址的效果
DHCP中继效果
路由的效果
