Cisco 3560实现DHCP中继代理

案例描述：
某公司的网络中有一个三层交换机SW1, 在公司的网络中每个部门一个VLAN、服务器一个独立的VLAN.在如图所示的环境中：

◆ Server处于VLAN10中，网段为192.168.1.0/24,其中DHCP服务的IP地址为192.168.1.2

◆ Sales部门处于VLAN20中，网段为192.168.2.0/24

◆ HR部门处于VLAN30中，网段为192.168.3.0/24
案例目的：

实现Sales和HR部门的所有的客户机能自动到DHCP服务上获得IP地址
案例注意点：

在部署环境的时候，所有的计算机使用微软的操作系统，其中 DHCP服务器使用微软的Windows Server 2008 R2操作系统；交换机使用Cisco 3560三层交换机。
案例实现：

一.按照要求连接好网络设备。

二.网络配置
交换机的基本配置

Switch>enable

Switch#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

sw1(config)#hostname sw1

sw1(config)#no ip domain lookup

sw1(config)#line console 0

sw1(config-line)#exec-timeout 0 0

sw1(config-line)#logging synchronous
2. 创建VLAN

方法一：

SW1(config)#vlan 10

SW1(config-vlan)#name Server

SW1(config-vlan)#vlan 20

SW1(config-vlan)#name Sales

SW1(config-vlan)#vlan 30

SW1(config-vlan)#name HR
方法二：

SW1#vlan database

% Warning: It is recommended to configure VLAN from config mode,

as VLAN database mode is being deprecated. Please consult user

documentation for configuring VTP/VLAN in config mode.

SW1(vlan)#vlan 10 name Server

VLAN 10 modified:

Name: Server

SW1(vlan)#vlan 20 name Sales

VLAN 20 modified:

Name: Sales

SW1(vlan)#vlan 30 name HR

VLAN 30 modified:

Name: HR

SW1(vlan)#exit

APPLY completed.

Exiting....
把相应的接口加入的相应VLAN中

SW1(config)#interface fastEthernet 0/4

SW1(config-if)#switchport mode access

SW1(config-if)#switchport access vlan 10

SW1(config-if)#exit

SW1(config)#interface fastEthernet 0/5

SW1(config-if)#switchport mode access

SW1(config-if)#switchport access vlan 20

SW1(config-if)#exit

SW1(config)#interface fastEthernet 0/6

SW1(config-if)#switchport mode access

SW1(config-if)#switchport access vlan 30
查看配置

SW1#sh vlan brief

VLAN Name Status Ports

---- -------------------------------- --------- -------------------------------

1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/7

Fa0/8, Fa0/9, Fa0/10, Fa0/11

Fa0/12, Fa0/13, Fa0/14, Fa0/15

Fa0/16, Fa0/17, Fa0/18, Fa0/19

Fa0/20, Fa0/21, Fa0/22, Fa0/23

Fa0/24

10 Server active Fa0/4

20 Sales active Fa0/5

30 HR active Fa0/6

1002 fddi-default active

1003 token-ring-default active

1004 fddinet-default active

1005 trnet-default active

5. 配置SVI端口

SW1(config)#interface vlan 10

%LINK-5-CHANGED: Interface Vlan10, changed state to up

SW1(config-if)#ip address 192.168.1.1 255.255.255.0

SW1(config-if)#no shutdown

SW1(config-if)#int vlan 20

%LINK-5-CHANGED: Interface Vlan20, changed state to up

SW1(config-if)#ip address 192.168.2.1 255.255.255.0

SW1(config-if)#int vlan 30

%LINK-5-CHANGED: Interface Vlan30, changed state to up

SW1(config-if)#ip add 192.168.3.1 255.255.255.0

SW1(config-if)#no sh
验证

SW1#sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

C 192.168.1.0/24 is directly connected, Vlan10

C 192.168.2.0/24 is directly connected, Vlan20

C 192.168.3.0/24 is directly connected, Vlan30
为客户机所属VLAN配置中继代理

SW1(config)#int vlan 20

SW1(config-if)#ip helper-address 192.168.1.2

SW1(config-if)#int vlan 30

SW1(config-if)#ip helper-address 192.168.1.2