基本步骤：
1) 创建虚接口VLAN 10、20，并且配置IP地址
2) 起路由协议保证可以通
3) 将接口划到相应的vlan中
4) 在虚接口vlan 10下打ip helper address
3550的配置：
hostname 3550
!
!
ip subnet-zero
ip routing
ip dhcp relay information option
!
interface FastEthernet0/4
description connect to DHCP server
switchport access vlan 20
switchport mode access
!
interface FastEthernet0/14
description connect to work01
switchport access vlan 10
switchport mode access
!
interface FastEthernet0/20
description connect to work02
switchport access vlan 10
switchport mode access
!

interface Vlan10
description place workgroup
ip address 172.16.10.1 255.255.255.0
ip helper-address 172.17.10.2
！指向服务器的地址
interface Vlan20
description place servers
ip address 172.17.10.1 255.255.255.0
!
router ospf 10
log-adjacency-changes
network 172.16.0.0 0.0.255.255 area 0
network 172.17.0.0 0.0.255.255 area 0
！起路由协议


SERVER的配置
no ip routing
！仿真成一台PC
ip dhcp excluded-address 172.16.10.1 172.16.10.2
ip dhcp pool test01
network 172.16.10.0 255.255.255.0
default-router 172.16.10.1
!
interface Ethernet0/0
ip address 172.17.10.2 255.255.255.0
!
ip default-gateway 172.17.10.1
！指定网关 vlan20的地址

另外两台路由器仿真成PC使用动态获取IP
No ip routing
interface Ethernet0/0
ip address dhcp

以上完成后，查看work01 看看是否有DHCP获取到地址
work01#sho ip int b
Interface IP-Address OK? Method Status Protocol
Ethernet0/0 172.16.10.4 YES DHCP up up
work01#sho ip route
Default gateway is 172.16.10.1
Host Gateway Last Use Total Uses Interface
ICMP redirect cache is empty

[ 本帖最后由 hnza001 于 2007-3-19 00:17 编辑 ]

学些一下了！

实际环境学习过了
还是支持下，巩固了

非常好，