DHCP中繼 動態主機配置協議中繼 在路由器上配置DHCP在三層交換機上設置DHCP中繼 Cisco

DHCP：

https://blog.csdn.net/aiwo1376301646/article/details/105551479

DHCP中繼：

也可以在路由器上配置DHCP，然後在三層交換機上設置DHCP中繼，DHCP客戶端通過三層交換機中繼獲取IP地址

路由器上實現dhcp的優點：

給多個三層交換機的多個相同vlan配置，不用再對每一個三層交換機進行配置

網絡拓撲圖：

代碼：

S1：
en
conf t
host s1
no ip domain-lookup
vlan 2
exit
vlan 3
exit
vlan 4
exit
int vlan 2
ip address 192.168.2.254 255.255.255.0
int vlan 3
ip address 192.168.3.254 255.255.255.0
int vlan 4
ip address 192.168.4.254 255.255.255.0
int f0/1
switchport access vlan 2
int f0/2
switchport access vlan 3
int f0/3
switchport access vlan 4
Int f0/4
No switchport
Ip address 192.168.5.2 255.255.255.252
ip routing
Route rip
Network 192.168.2.0
Network 192.168.3.0
Network 192.168.4.0
Network 192.168.5.0
!Service dhcp
!這行代碼可有可無
int vlan 2
Ip helper-address 192.168.5.1
!給VLAN2的主機通過中繼路由器192.168.5.1的DHCP服務分配IP地址
int vlan 3
Ip helper-address 192.168.5.1
int vlan 4
Ip helper-address 192.168.5.1

R1:
En
Conf t
Host r1
No ip domain-lookup
Int g0/0
Ip address 192.168.5.1 255.255.255.252
No shut
Int g0/1
Ip address 192.168.6.254 255.255.255.0
No shut
Exit
Route rip
Network 192.168.5.0
Network 192.168.6.0
Service dhcp
!啓動dhcp服務
Ip dhcp excluded-address 192.168.2.254
!排除不拿來分配的單個地址
Ip dhcp pool vlan-2
!建立一個地址池，名字由字母加數字構成
Network 192.168.2.0 255.255.255.0
Default-router 192.168.2.254
!指定客戶機的網關地址
Dns-server 8.8.8.8
!給定客戶機dns服務器地址，8.8.8.8是google的
Exit
Ip dhcp excluded-address 192.168.3.254
Ip dhcp pool vlan-3
Network 192.168.3.0 255.255.255.0
Default-router 192.168.3.254
Dns-server 8.8.8.8
Exit
Ip dhcp excluded-address 192.168.4.254
Ip dhcp pool vlan-4
Network 192.168.4.0 255.255.255.0
Default-router 192.168.4.254
Dns-server 114.114.114.114
! 114.114.114.114這個是中國電信的
Exit
Ip dhcp excluded-address 192.168.6.254
Ip dhcp pool vlan-6
Network 192.168.6.0 255.255.255.0
Default-router 192.168.6.254
Dns-server 114.114.114.114
Exit

DHCP配置結果：