DHCPRelay配置教程

如果DHCP客户端和DHCP服务器不在同一网段内&＃xff0c;需要DHCP中继负责DHCP服务器与DHCP客户端之间的DHCP报文转发&＃xff0c;这样可以避免在每个网段部署DHCP服务器&＃xff0c;节约成本&＃xff0c;方便管理。

DHCP服务器和DHCP客户端之间的DHCP报文中继次数不能超过16次&＃xff0c;否则DHCP报文将被丢弃。

设备作为DHCP中继时&＃xff0c;如果使能了STP功能&＃xff0c;可能会造成地址分配较慢。STP功能缺省处于使能状态&＃xff0c;如果确认不需要使能STP功能&＃xff0c;可以执行命令undo stp enable去使能STP功能。

当DHCP客户端与DHCP服务器经过三层设备相连时&＃xff08;不在同一网段&＃xff09;&＃xff0c;需要DHCP中继设备在中间担当一个代理角色&＃xff0c;负责转发DHCP客户端与DHCP服务器之间的通信。

DHCP中继必须与DHCP客户端所在网段直连&＃xff0c;但不一定要与DHCP服务器所在网段直连&＃xff0c;但要与DHCP服务器所在网段路由通畅。

DHCP中继模式仅可工作在三层模式的接口&＃xff0c;DHCP中继设备必须使能DHCP功能

1. 将交换机上相应的接口划分到相应的VLAN中
2. 在SW1上配置SVI&＃xff08;相当于网关&＃xff09;
3. 在R1上配置两个DHCP的地址池&＃xff0c;并在接口下开启全局分配IP地址
4. 在SW1启用DHCP中继功能

[SW1]int vlan 10 //配置VLAN10
[SW1-Vlanif10]dhcp select relay //配置DHCP中继
[SW1-Vlanif10]dhcp relay server-ip 192.168.254.2 //指向DHCP服务器的IP地址
[SW1-Vlanif10]quit //退出

实验详细配置步骤&＃xff1a;

划分VLAN

SW2——将接口设置为相应的链路并加入VLAN

上联口打trunk链路
下联口打access链路

system-view //进入全局配置模式
[Huawei]undo info-center enable //关闭信息告警提示
[Huawei]sysname SW2 //改名
[SW2]vlan 10 //创建VLAN10
[SW2-vlan10]quit //退出
[SW2]int e0/0/2 //进入接口
[SW2-Ethernet0/0/2]port link-type access //将接口模式修改为access链路
[SW2-Ethernet0/0/2]port default vlan 10 //允许VLAN 10通过
[SW2-Ethernet0/0/2]quit //退出
[SW2]int e0/0/1 //进入接口
[SW2-Ethernet0/0/1]port link-type trunk //将接口模式修改为trunk链路
[SW2-Ethernet0/0/1]port trunk allow-pass vlan 10 //允许VLAN 10通过
[SW2-Ethernet0/0/1]quit //退出
[SW2]


SW3——将接口设置为相应的链路并加入VLAN

上联口打trunk链路
下联口打access链路

system-view //进入全局配置模式
[Huawei]undo info-center enable //关闭信息告警提示
[Huawei]sysname SW3 //改名
[SW3]vlan 20 //创建VLAN20
[SW3-vlan20]quit //退出
[SW3]int e0/0/2 //进入接口
[SW3-Ethernet0/0/2]port link-type access //将接口模式修改为access链路
[SW3-Ethernet0/0/2]port default vlan 20 //允许VLAN 20通过
[SW3-Ethernet0/0/2]quit //退出
[SW3]int e0/0/1 //进入接口
[SW3-Ethernet0/0/1]port link-type trunk //将接口模式修改为trunk链路
[SW3-Ethernet0/0/1]port trunk allow-pass vlan 20 //允许VLAN 20通过
[SW3-Ethernet0/0/1]quit //退出
[SW3]


SW1——将接口设置相应的链路并加入VLAN

下联口打trunk链路
上联口打access链路

system-view //进入全局配置模式
[Huawei]undo info-center enable //关闭信息告警提示
[Huawei]sysname SW1 //改名
[SW1]vlan batch 10 20 100 //创建VLAN 10、VLAN 20、VLAN 100
[SW1]int g0/0/2 //进入接口
[SW1-GigabitEthernet0/0/2]port link-type trunk //将接口模式修改为trunk链路
[SW1-GigabitEthernet0/0/2]port trunk allow-pass vlan 10 //允许VLAN 10通过
[SW1-GigabitEthernet0/0/2]quit //退出
[SW1]int g0/0/3 //进入接口
[SW1-GigabitEthernet0/0/3]port link-type trunk //将接口模式修改为trunk链路
[SW1-GigabitEthernet0/0/3]port trunk allow-pass vlan 20 //允许VLAN 20通过
[SW1-GigabitEthernet0/0/3]quit //退出
[SW1]int g0/0/1 //进入接口
[SW1-GigabitEthernet0/0/1]port link-type access //将接口模式修改为access链路
[SW1-GigabitEthernet0/0/1]port default vlan 100 //允许VLAN 100通过
[SW1-GigabitEthernet0/0/1]quit //退出
[SW1]


配置SVI

SW1——配置SVI

作为PC的网关

[SW1]int vlan 10 //进入VLAN 10
[SW1-Vlanif10]ip address 192.168.10.1 24 //设置IP地址
[SW1-Vlanif10]quit //退出
[SW1]int vlan 20 //进入VLAN 20
[SW1-Vlanif20]ip address 192.168.20.1 24 //设置IP地址
[SW1-Vlanif20]quit //退出
[SW1]int vlan 100 //进入VLAN 100
[SW1-Vlanif100]ip address 192.168.254.1 24 //设置IP地址
[SW1-Vlanif100]quit //退出
[SW1]


查看接口IP地址

SW1——查看接口IP地址

[SW1]dis ip in brief //查看接口IP地址
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 5
The number of interface that is DOWN in Physical is 1
The number of interface that is UP in Protocol is 4
The number of interface that is DOWN in Protocol is 2Interface IP Address/Mask Physical Protocol
MEth0/0/1 unassigned down down
NULL0 unassigned up up(s)
Vlanif1 unassigned up down
Vlanif10 192.168.10.1/24 up up
Vlanif20 192.168.20.1/24 up up
Vlanif100 192.168.254.1/24 up up
[SW1]


配置接口IP地址

R1-DHCP——配置接口IP地址

system-view //进去全局配置模式
[Huawei]undo info-center enable //关闭信息告警提示
[Huawei]sysname R1-DHCP //改名
[R1-DHCP]int g0/0/0 //进入接口
[R1-DHCP-GigabitEthernet0/0/0]ip address 192.168.254.2 24 //配置IP地址
[R1-DHCP-GigabitEthernet0/0/0]quit //退出
[R1-DHCP]


配置静态路由

R1-DHCP——配置一条静态路由

相当于服务器的网关

[R1-DHCP]ip route-static 0.0.0.0 0 192.168.254.1 //配置一条静态路由


配置DHCP地址池

R1-DHCP——配置DHCP地址池

[R1-DHCP]dhcp enable //启动DHCP
[R1-DHCP]ip pool VLAN10 //配置DHCP名称VLAN 10
[R1-DHCP-ip-pool-VLAN10]network 192.168.10.0 mask 24 //配置下发地址的网段
[R1-DHCP-ip-pool-VLAN10]gateway-list 192.168.10.1 //配置下发地址的网关
[R1-DHCP-ip-pool-VLAN10]dns-list 8.8.8.8 //配置下发地址的DNS
[R1-DHCP-ip-pool-VLAN10]quit //退出
[R1-DHCP]ip pool VLAN20 //配置DHCP名称VLAN 10
[R1-DHCP-ip-pool-VLAN20]network 192.168.20.0 mask 24 //配置下发地址的网段
[R1-DHCP-ip-pool-VLAN20]gateway-list 192.168.20.1 //配置下发地址的网关
[R1-DHCP-ip-pool-VLAN20]dns-list 8.8.8.8 //配置下发地址的DNS
[R1-DHCP-ip-pool-VLAN20]quit //退出
[R1-DHCP]


开启全局分配IP地址

R1-DHCP——在接口下开启全局分配IP地址

[R1-DHCP]int g0/0/0 //进入接口
[R1-DHCP-GigabitEthernet0/0/0]dhcp select global //接口下启动DHCP全局模式
[R1-DHCP-GigabitEthernet0/0/0]quit //退出
[R1-DHCP]


配置DHCP中继

SW1——配置DHCP中继

[SW1]dhcp enable //开启DHCP服务
[SW1]int vlan 10 //配置VLAN10
[SW1-Vlanif10]dhcp select relay //配置DHCP中继
[SW1-Vlanif10]dhcp relay server-ip 192.168.254.2 //指向DHCP服务器的IP地址
[SW1-Vlanif10]quit //退出
[SW1]int vlan 20 //配置VLAN20
[SW1-Vlanif20]dhcp select relay //配置DHCP中继
[SW1-Vlanif20]dhcp relay server-ip 192.168.254.2 //指向DHCP服务器的IP地址
[SW1-Vlanif20]quit //退出
[SW1]


测试

PC1——查看是否获取到IP地址

PC>ipconfig //查看IP地址Link local IPv6 address...........: fe80::5689:98ff:feb5:67dd
IPv6 address......................: :: / 128
IPv6 gateway......................: ::
IPv4 address......................: 192.168.10.254 //成功获取到相应的IP地址
Subnet mask.......................: 255.255.255.0
Gateway...........................: 192.168.10.1
Physical address..................: 54-89-98-B5-67-DD
DNS server........................: 8.8.8.8PC>


PC2——查看是否获取到IP地址

PC>ipconfig //查看IP地址Link local IPv6 address...........: fe80::5689:98ff:fef9:19d6
IPv6 address......................: :: / 128
IPv6 gateway......................: ::
IPv4 address......................: 192.168.20.254 //成功获取到相应的IP地址
Subnet mask.......................: 255.255.255.0
Gateway...........................: 192.168.20.1
Physical address..................: 54-89-98-F9-19-D6
DNS server........................: 8.8.8.8PC>