网络拓扑图： 路由器装备： Current configuration : 1351 bytes ! version 12.2 no service timestamps log datetime msec no service timestamps debug datetime msec no service password-encryption ! hostname Router ! ip http://www.aaafaipiao.com/linked/20130305.dodhcp excluded-address 192.168.20.1 ip dhcp excluded-address 192.168.20.2 ip dhcp excluded-address 192.168.20.4 ip dhcp excluded-address 192.168.20.3 ip dhcp excluded-address 192.168.30.1 ip dhcp excluded-address 192.168.30.2 ip dhcp excluded-address 192.168.30.3 ip dhcp excluded-address 192.168.30.4 ! ip dhcp pool vlan20 network 192.168.20.0 255.255.255.0 default-router 192.168.20.1 dns-server 202.96.134.133 ip dhcp pool vlan30 network 192.168.30.0 255.255.255.0 default-router 192.168.30.1 dns-server 202.96.134.133 ! interface FastEthernet0/0 no ip address duplex auto speed auto ! interface FastEthernet0/0.1 encapsulation dot1Q 20 ip address 192.168.30.1 255.255.255.0 ! interface FastEthernet0/0.2 encapsulation dot1Q 30 ip address 192.168.20.1 255.255.255.0 ! interface FastEthernet1/0 no ip address duplex auto speed auto shutdown ! interface Serial2/0 no ip address clock rate 2000000 shutdown ! interface Serial3/0 no ip address clock rate 2000000 shutdown ! interface FastEthernet4/0 no ip address shutdown ! interface FastEthernet5/0 no ip address shutdown ! ip classless ! line con 0 line vty 0 4 login ! end 交换机装备： Current configuration : 1260 bytes ! version 12.2 no service timestamps log datetime msec no service timestamps debug datetime msec no service password-encryption ! hostname Switch ! ! spanning-tree mode pvst ! interface FastEthernet0/1 switchport mode trunk ! interface FastEthernet0/2 switchport access vlan 20 switchport mode access ! interface FastEthernet0/3 switchport access vlan 20 switchport mode access ! interface FastEthernet0/4 switchport access vlan 30 switchport mode access ! interface FastEthernet0/5 switchport access vlan 30 switchport mode access ! line con 0 ! line vty 0 4 login line vty 5 15 login ! end 完成作用：PC0,PC1主动从路由器取得VLAN 30网段的IP地址；PC2,PC3主动从路由器取得VLAN 20网段的IP地址。http://www.kp1234.info/linked/20130305.do
