大家好！本人刚学CISCO配置，现在研究实现了DHCP功能的同一路由下VLAN间的互访，但是发现如果实现了DHCP，VLAN间就没法互访了，具体配置如下：
路由器（CISCO 2811）（拓扑图就不上了，简单说一下，2811 f0/0,f0/1分别接两个2960交换机f0/24 ，f0/24启用了trunk链路）
interface FastEthernet0/0
no ip address
duplex auto
speed auto
!
interface FastEthernet0/0.1
encapsulation dot1Q 10
ip address 192.168.10.1 255.255.255.0
!
interface FastEthernet0/0.2
encapsulation dot1Q 20
ip address 192.168.20.1 255.255.255.0
!
interface FastEthernet0/1
no ip address
duplex auto
speed auto
!
interface FastEthernet0/1.1
encapsulation dot1Q 30
ip address 192.168.30.1 255.255.255.0
!
interface FastEthernet0/1.2
encapsulation dot1Q 40
ip address 192.168.40.1 255.255.255.0
ip dhcp pool vlan10
network 192.168.10.0 255.255.255.0
default-router 192.168.10.1
ip dhcp pool vlan20
network 192.168.20.0 255.255.255.0
default-router 192.168.20.1
ip dhcp pool vlan30
network 192.168.30.0 255.255.255.0
default-router 192.168.30.1
ip dhcp pool vlan40
network 192.168.40.0 255.255.255.0
default-router 192.168.40.1
交换机（CISCO 2960）
两个2960交换机，分别配置了VLAN 10 20 和30 40，并且指定了IP
交换机一
interface FastEthernet0/1
switchport access vlan 10
!
interface FastEthernet0/2
switchport access vlan 10
!
interface FastEthernet0/3
switchport access vlan 10
!
interface FastEthernet0/4
switchport access vlan 10
!
interface FastEthernet0/5
switchport access vlan 10
!
interface FastEthernet0/6
switchport access vlan 10
!
interface FastEthernet0/7
switchport access vlan 10
!
interface FastEthernet0/8
switchport access vlan 10
!
interface FastEthernet0/9
switchport access vlan 10
!
interface FastEthernet0/10
switchport access vlan 10
!
interface FastEthernet0/11
switchport access vlan 10
!
interface FastEthernet0/12
switchport access vlan 20
!
interface FastEthernet0/13
switchport access vlan 20
!
interface FastEthernet0/14
switchport access vlan 20
!
interface FastEthernet0/15
switchport access vlan 20
!
interface FastEthernet0/16
switchport access vlan 20
!
interface FastEthernet0/17
switchport access vlan 20
!
interface FastEthernet0/18
switchport access vlan 20
!
interface FastEthernet0/19
switchport access vlan 20
!
interface FastEthernet0/20
switchport access vlan 20
!
interface FastEthernet0/21
switchport access vlan 20
!
interface FastEthernet0/22
switchport access vlan 20
!
interface FastEthernet0/23
switchport access vlan 20
!
interface FastEthernet0/24
switchport trunk allowed vlan 10,20
switchport mode trunk
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Vlan1
no ip address
shutdown
!
interface Vlan10
ip address 192.168.10.1 255.255.255.0
!
interface Vlan20
ip address 192.168.20.1 255.255.255.0
交换机二
interface FastEthernet0/1
switchport access vlan 30
!
interface FastEthernet0/2
switchport access vlan 30
!
interface FastEthernet0/3
switchport access vlan 30
!
interface FastEthernet0/4
switchport access vlan 30
!
interface FastEthernet0/5
switchport access vlan 30
!
interface FastEthernet0/6
switchport access vlan 30
!
interface FastEthernet0/7
switchport access vlan 30
!
interface FastEthernet0/8
switchport access vlan 30
!
interface FastEthernet0/9
switchport access vlan 30
!
interface FastEthernet0/10
switchport access vlan 30
!
interface FastEthernet0/11
switchport access vlan 30
!
interface FastEthernet0/12
switchport access vlan 40
!
interface FastEthernet0/13
switchport access vlan 40
!
interface FastEthernet0/14
switchport access vlan 40
!
interface FastEthernet0/15
switchport access vlan 40
!
interface FastEthernet0/16
switchport access vlan 40
!
interface FastEthernet0/17
switchport access vlan 40
!
interface FastEthernet0/18
switchport access vlan 40
!
interface FastEthernet0/19
switchport access vlan 40
!
interface FastEthernet0/20
switchport access vlan 40
!
interface FastEthernet0/21
switchport access vlan 40
!
interface FastEthernet0/22
switchport access vlan 40
!
interface FastEthernet0/23
switchport access vlan 40
!
interface FastEthernet0/24
switchport trunk allowed vlan 30,40
switchport mode trunk
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Vlan1
no ip address
shutdown
!
interface Vlan30
ip address 192.168.30.1 255.255.255.0
!
interface Vlan40
ip address 192.168.40.1 255.255.255.0
现在的问题是：DHCP自动获取正常，但VLAN间无法互访，请高手指导一下，怎么样改写才能实现DHCP下的VLAN间互访（本人已实验过如果取消DHCP，手动指定PC的IP地址是能实现互访的）。
