DHCP自动分配IP

练习1

• 路由器

Router>en
Router#conf t
Router(config)#ip dhcp pool ip10 //创建DHCP地址池
Router(dhcp-config)#network 192.168.20.0 255.255.255.0 // 配置网络地址和子网掩码
Router(dhcp-config)#default-router 192.168.20.254 //配置默认网关
Router(dhcp-config)#dns-server 8.8.8.8 //配置DNS服务器
Router(dhcp-config)#ex
Router(config)#int g0/0
Router(config-if)#no shutdown 
Router(config-if)#ip add 192.168.20.254 255.255.255.0 // 配置ip地址

• show ip dhcp pool

Router#show ip dhcp pool

Pool ip10 :
 Utilization mark (high/low)    : 100 / 0
 Subnet size (first/next)       : 0 / 0 
 Total addresses                : 254
 Leased addresses               : 2
 Excluded addresses             : 0
 Pending event                  : none

 1 subnet is currently in the pool
 Current index        IP address range                    Leased/Excluded/Total
 192.168.20.1         192.168.20.1     - 192.168.20.254    2    / 0     / 254
Router#

练习2

• 路由器
• 配置192.168.10.254

Router(config)#ip dhcp pool ip10
Router(dhcp-config)#network 192.168.10.0 255.255.255.0
Router(dhcp-config)#default-router 192.168.10.254
Router(dhcp-config)#dns-server 8.8.8.8
Router(dhcp-config)#ex
Router(config)#int g0/1
Router(config-if)#no shutdown 
Router(config-if)#ip add 192.168.10.254 255.255.255.0
Router(config-if)#ex

• 配置192.168.20.254

Router(config)#ip dhcp pool ip20
Router(dhcp-config)#network 192.168.20.0 255.255.255.0
Router(dhcp-config)#default-router 192.168.20.254
Router(dhcp-config)#dns-server 8.8.8.8
Router(dhcp-config)#ex
Router(config)#int g0/2
Router(config-if)#no shutdown 
Router(config-if)#ip add 192.168.20.254 255.255.255.0
Router(config-if)#ex

• 配置服务器ip
• 服务器ip需要手动配置

• 

Router(config)#int g0/0
Router(config-if)#no shutdown 
Router(config-if)#ip add 172.168.100.254 255.255.255.0

• 配置DHCP中继模式

Router(config)#int g0/1
Router(config-if)#ip helper-address 172.16.100.100
Router(config-if)#ex
Router(config)#int g0/2
Router(config-if)#ip helper-address 172.16.100.100
Router(config-if)#ex

• 在服务器需设置DHCP起始IP，才可设置ip范围

show ip dhcp pool

• 可以看到添加的两个网段