DHCP snooping
这个任务主要是做DHCP Snooping。
DHCP服务器在路由器上，而SWA上有3个VLAN，分属于3个不同网段，
DHCP的请求报文是广播，因此必须在SWA上设置中继才能够传到路由器。
伪DHCP Server已经配置好，将发布172.22.1.1-99的地址池，网关172.22.1.254，DNS 9.9.9.9
配置步骤
(1) # 配置路由器。
[H3C] interface g 0/0
[[H3C-GigabitEthernet0/0]] ip address 10.1.1.2 30
[[H3C-GigabitEthernet0/0]] quit
#启用 DHCP 服务。
[H3C] dhcp enable
#配置 DHCP 地址池 1，为来自 192.168.1.0/24网段内的客户端分配地址。
[H3C] dhcp server ip-pool 1
[H3C-dhcp-pool-0] network 192.168.10.0 mask 255.255.255.0
[H3C-dhcp-pool-0] dns-list 8.8.8.8
[H3C-dhcp-pool-0] gateway-list 192.168.10.254
[H3C-dhcp-pool-0] quit
#配置 DHCP 地址池 2，为来自 192.168.20.0/24网段内的客户端分配地址。
[H3C] dhcp server ip-pool 2
[H3C-dhcp-pool-0] network 192.168.20.0 mask 255.255.255.0
[H3C-dhcp-pool-0] dns-list 8.8.8.8
[H3C-dhcp-pool-0] gateway-list 192.168.20.254
[H3C-dhcp-pool-0] quit
#配置 DHCP 地址池 3，为来自 192.168.30.0/24网段内的客户端分配地址。
[H3C] dhcp server ip-pool 3
[H3C-dhcp-pool-0] network 192.168.30.0 mask 255.255.255.0
[H3C-dhcp-pool-0] dns-list 8.8.8.8
[H3C-dhcp-pool-0] gateway-list 192.168.30.254
[H3C-dhcp-pool-0] quit
#配置静态路由到192.168.0.0/16网段
[H3C]ip route-static 192.168.0.0 16 10.1.1.1
(2)# 配置 SWA交换机。
#建立vlan，并且配置各接口的 IP 地址。
[H3C]vlan 10
[H3C-vlan10]quit
[H3C]vlan 20
[H3C-vlan20]quit
[H3C]vlan 30
[H3C-vlan30]quit
[H3C]inter range g 1/0/1 to g 1/0/5
[H3C-if-range]port link-type access
[H3C-if-range]port access vlan 10
[H3C-if-range]quit
[H3C]inter range g 1/0/6 to g 1/0/10
[H3C-if-range]port link-type access
[H3C-if-range]port access vlan 20
[H3C-if-range]quit
[H3C]inter range g 1/0/11 to g 1/0/15
[H3C-if-range]port link-type access
[H3C-if-range]port access vlan 30
[H3C-if-range]quit
[H3C]inter vlan 10
[H3C-Vlan-interface10]ip add 192.168.10.254 24
[H3C-Vlan-interface10]quit
[H3C]inter vlan 20
[H3C-Vlan-interface20]ip add 192.168.20.254 24
[H3C-Vlan-interface20]quit
[H3C]inter vlan 30
[H3C-Vlan-interface30]ip add 192.168.30.254 24
[H3C-Vlan-interface30]quit
[H3C]
[H3C]inter g 1/0/23
[H3C-GigabitEthernet1/0/23]port link-t
[H3C-GigabitEthernet1/0/23]ip add 10.1.1.1 30
[H3C-GigabitEthernet1/0/23]quit
(3)#配置DHCP中继（SWA交换机）
#启用 DHCP 服务。
[H3C] dhcp enable
#配置 VLAN 接口 10 工作在 DHCP 中继模式。
[H3C] interface vlan-interface 10
[H3C-Vlan-interface10] dhcp select relay
#配置 DHCP 服务器的地址。
[H3C-Vlan-interface10] dhcp relay server-address 10.1.1.2
[H3C-Vlan-interface10] quit
配置 VLAN 接口 20 工作在 DHCP 中继模式。
[H3C] interface vlan-interface 20
[H3C-Vlan-interface20] dhcp select relay
[H3C-Vlan-interface20] dhcp relay server-address 10.1.1.2
[H3C-Vlan-interface20] quit
#配置 VLAN 接口 30 工作在 DHCP 中继模式。
[H3C] interface vlan-interface 30
[H3C-Vlan-interface30] dhcp select relay
[H3C-Vlan-interface30] dhcp relay server-address 10.1.1.2
[H3C-Vlan-interface30] quit(4)#配置DHCP Snooping（SWB交换机）
#启用 DHCP Snooping 功能。
[H3C] dhcp snooping enable
#设置 GigabitEthernet1/0/21 端口为信任端口。
[H3C] interface GigabitEthernet 1/0/21
[H3C-GigabitEthernet1/0/21] dhcp snooping trust
[H3C-GigabitEthernet1/0/21] quit
#在 GigabitEthernet1/0/1 上启用 DHCP Snooping 表项功能。
[H3C] interface GigabitEthernet 1/0/1
[H3C-GigabitEthernet1/0/1] dhcp snooping binding record
[H3C-GigabitEthernet1/0/1] quit