switch分解试验部分-LAB12:DHCP中继

LAB12:DHCP中继

一、实验目的
1、掌握DHCP中继的应用

二、实验内容
[align=left]拓扑图：[/align]




[align=left]需求： [/align]
[align=left]1、VLAN 10、VLAN 20内的PC能够从DHCP Server（Server-PT）动态获得IP地址； [/align]
[align=left]2 、DHCP Server（Server-PT）属于VLAN 101； [/align]
[align=left] [/align]
[align=left]三、实验配置 [/align]
[align=left]配置思路： [/align]
[align=left]DHCP工作时使用广播地址，同时PC和DHCP Server又不在同一VLAN中，而VLAN拥有分割广播域的作用，从而导致PC不能从DHCP Server 获取IP地址。这就需要我们在负责VLAN间路由的3560-24PS 的交换机上启用DHCP中继来解决问题。 [/align]
[align=left]配置 [/align]
[align=left]1、开启3560-24PS的DHCP服务功能 [/align]
[align=left]Switch(config)#service dhcp [/align]
[align=left] [/align]
[align=left]2、开启路由功能 [/align]
[align=left]Switch(config)#ip routing [/align]
[align=left] [/align]
[align=left]3、开启DHCP中继功能 [/align]
[align=left]Switch(config)#ip dhcp relay information option [/align]
[align=left]Switch(config)#interface vlan 10[/align]
[align=left]Switch(config-if)#ip helper-address 192.168.101.1 （设置中继目标地址为DHCP Server ） [/align]
[align=left] [/align]
[align=left]验证： [/align]
[align=left]Switch#debug ip dhcp server packet [/align]
[align=left]*Mar 1 01:42:58.663: DHCPD: incoming interface name is Vlan10 [/align]
[align=left]*Mar 1 01:42:58.663: DHCPD: Looking up binding using address 192.168.10.254 [/align]
[align=left]*Mar 1 01:42:58.663: DHCPD: setting giaddr to 192.168.10.254. [/align]
[align=left]*Mar 1 01:42:58.663: DHCPD: adding relay information option. [/align]
[align=left]*Mar 1 01:42:58.663: DHCPD: BOOTREQUEST from 0100.2264.4bab.eb forwarded to 192.168.20.1. [/align]
[align=left]*Mar 1 01:42:58.667: DHCPD: incoming interface name is Vlan20 [/align]
[align=left]*Mar 1 01:42:58.667: DHCPD: forwarding BOOTREPLY to client 0022.644b.abeb. [/align]
[align=left]*Mar 1 01:42:58.667: old_giaddr = 0.0.0.0, giaddr=0.0.0.0, flag=0 [/align]
[align=left]*Mar 1 01:42:58.667: DHCPD: Option82 is currently: [/align]
[align=left]*Mar 1 01:42:58.667: 020c020a0000c0a80afe0a000000 [/align]
[align=left]*Mar 1 01:42:58.667: DHCPD: Removing option82 information [/align]
[align=left]*Mar 1 01:42:58.667: DHCPD: Option82 is removed [/align]
[align=left]*Mar 1 01:42:58.667: DHCPD: broadcasting BOOTREPLY to client 0022.644b.abeb. [/align]
[align=left]*Mar 1 01:43:02.731: DHCPD: incoming interface name is Vlan10 [/align]
[align=left]*Mar 1 01:43:02.731: DHCPD: Looking up binding using address 192.168.10.254 [/align]
[align=left]*Mar 1 01:43:02.731: DHCPD: setting giaddr to 192.168.10.254. [/align]
[align=left]*Mar 1 01:43:02.731: DHCPD: adding relay information option. [/align]
[align=left]*Mar 1 01:43:02.731: DHCPD: BOOTREQUEST from 0100.2264.4bab.eb forwarded to 192.168.20.1. [/align]
[align=left]*Mar 1 01:43:02.735: DHCPD: incoming interface name is Vlan20 [/align]
[align=left]*Mar 1 01:43:02.735: DHCPD: forwarding BOOTREPLY to client 0022.644b.abeb.[/align]
[align=left]*Mar 1 01:43:02.735: old_giaddr = 0.0.0.0, giaddr=0.0.0.0, flag=0 [/align]
[align=left]*Mar 1 01:43:02.735: DHCPD: Option82 is currently: [/align]
[align=left]*Mar 1 01:43:02.735: 020c020a0000c0a80afe0a000000 [/align]
[align=left]*Mar 1 01:43:02.735: DHCPD: Removing option82 information [/align]
[align=left]*Mar 1 01:43:02.735: DHCPD: Option82 is removed [/align]
[align=left]*Mar 1 01:43:02.735: DHCPD: broadcasting BOOTREPLY to client 0022.644b.abeb. [/align]
[align=left] [/align]
[align=left]四、应用场景 [/align]
[align=left]当使用Windows2003、Windows2008、Linux等为DHCP Server，并且和PC不在同一网段时；[/align]