HCIA--DHCP: 动态主机配置协议 （复习）

DHCP: 动态主机配置协议  -- 同一分发管理ip地址

基于UDP 67/68端口工作  

网络中存在DHCP的服务器为需要自动生成ip地址的设备分配ip地址；--C/S模型

成为DHCP服务器的条件：

1. 该设备存在接口或网卡连接到所要分发ip地址的广播域内
2. 该接口或网卡必须已经配置合法ip地址，且可以正常通讯；

第一步：[Huawei]dhcp enable   先开启设备的dhcp服务一台设备上可以创建多个池塘，但一个池塘只能服务一个广播域第二步：[Huawei]ip pool wangcai  创建名为wangcai的dhcp池塘第三步：[Huawei-ip-pool-wangcai]network 192.168.1.0 mask 24 绑定接口第四步：[Huawei-ip-pool-wangcai]gateway-list 192.168.1.1  该网段网关地址第五步：[Huawei-ip-pool-wangcai]dns-list 192.168.2.11 114.114.114.114 DNS服务器地址第六步[Huawei]interface Eth0/0/0[Huawei-Ethernet0/0/0]dhcp select global  切记：最后还需要在路由器进行地址分配的接口上再单独开启dhcp服务

客户端基于UDP，源端口68，目标端口67进行广播请求 -- 源ip-0.0.0.0（无效地址，代表本地无地址）目255.255.255.255

服务器在收到客户端的请求后，回复提议-- 源端口67，目标68；源ip-本地地址，目标ip（255.255.255.255）华为设备的目标ip为计划分配给客户端的ip --- 主要还是靠目标的MAC地址来将提议发送给客户

客户端在收到提议后，若确定使用该ip，将应答服务端；服务端最终ack确认后，该ip地址才可以被真正的使用；

注：过程中服务端与客户端均会使用ARP来进行地址冲突检测，确认该地址唯一时，才进行分配和使用；

dhcp抓包过程; 

[Huawei-ip-pool-a]excluded-ip-address 192.168.1.10 192.168.1.20  排除地址 -- 该池塘不能分配的ip地址

[Huawei-ip-pool-a]lease day  0 hour 0 minute 30 修改租期，默认24小时

实验部分：

	
[Huawei-ip-pool-a]display current-configuration 
#
sysname Huawei
#
dhcp enable
#
ip pool bgateway-list 192.168.2.1network 192.168.2.0 mask 255.255.255.0dns-list 192.168.1.2
#
ip pool agateway-list 192.168.1.1network 192.168.1.0 mask 255.255.255.0dns-list 192.168.1.2
#
aaaauthentication-scheme defaultauthorization-scheme defaultaccounting-scheme defaultdomain defaultdomain default_adminlocal-user admin password cipher OOCM4m($F4ajUn1vMEIBNUw#local-user admin service-type http
#
firewall zone Localpriority 16
#
interface Ethernet0/0/0ip address 192.168.1.1 255.255.255.0dhcp select global
#
interface Ethernet0/0/1ip address 192.168.2.1 255.255.255.0dhcp select global[Huawei-ip-pool-a]dis ip interface brief 
*down: administratively down
!down: FIB overload down
^down: standby
(l): loopback
(s): spoofing
(d): Dampening Suppressed
The number of interface that is UP in Physical is 3
The number of interface that is DOWN in Physical is 8
The number of interface that is UP in Protocol is 3
The number of interface that is DOWN in Protocol is 8Interface                         IP Address/Mask      Physical   Protocol  
Ethernet0/0/0                     192.168.1.1/24       up         up        
Ethernet0/0/1                     192.168.2.1/24       up         up        
GigabitEthernet0/0/0              unassigned           down       down      
GigabitEthernet0/0/1              unassigned           down       down      
GigabitEthernet0/0/2              unassigned           down       down      
GigabitEthernet0/0/3              unassigned           down       down      
NULL0                             unassigned           up         up(s)     
Serial0/0/0                       unassigned           down       down      
Serial0/0/1                       unassigned           down       down      
Serial0/0/2                       unassigned           down       down      
Serial0/0/3                       unassigned           down       down      
[Huawei-ip-pool-a]

PC>ipconfigLink local IPv6 address...........: fe80::5689:98ff:fe4a:742d
IPv6 address......................: :: / 128
IPv6 gateway......................: ::
IPv4 address......................: 192.168.1.254
Subnet mask.......................: 255.255.255.0
Gateway...........................: 192.168.1.1
Physical address..................: 54-89-98-4A-74-2D
DNS server........................: 192.168.1.2

Link local IPv6 address...........: fe80::5689:98ff:fe97:2d3f
IPv6 address......................: :: / 128
IPv6 gateway......................: ::
IPv4 address......................: 192.168.2.254
Subnet mask.......................: 255.255.255.0
Gateway...........................: 192.168.2.1
Physical address..................: 54-89-98-97-2D-3F
DNS server........................: 192.168.1.2