DHCP请求失败，正在使用APIPA

Question

因此，我在数据包跟踪器中有以下网络配置。

路由器配置为DHCP。交换机上的端口配置为访问模式--用于那些属于PC机的端口。未使用的端口被关闭。交换机之间的端口和交换机与路由器之间的端口被配置为中继端口。所有连接到直接连接到S1的R1的PC机都从路由器获取IP地址。然而，连接到S2和S3的PC并没有收到消息"DHCP请求失败，APIPA正在使用“。有什么问题吗？

下面是配置的链接- https://1drv.ms/u/s!AiRtffZ-QpFphY8iof_YGdcuua3KXw

R1:

的配置

ip dhcp pool Head  
 network 10.10.10.0 255.255.255.0  
 default-router 10.10.10.1  
ip dhcp pool R&D  
 network 10.10.20.0 255.255.255.0  
 default-router 10.10.20.1  
ip dhcp pool M&S  
 network 10.10.30.0 255.255.255.0  
 default-router 10.10.30.1  
ip dhcp pool Lab  
 network 10.10.40.0 255.255.255.0  
 default-router 10.10.40.1  
ip dhcp pool WS  
 network 10.10.50.0 255.255.255.0  
 default-router 10.10.50.1  

no ip cef  
no ipv6 cef  

spanning-tree mode pvst  

interface FastEthernet0/0  
 no ip address  
 ip nat inside  
 duplex auto  
 speed auto  
!  
interface FastEthernet0/0.1  
 encapsulation dot1Q 1 native  
 ip address 10.10.1.1 255.255.255.0  
!  
interface FastEthernet0/0.10  
 encapsulation dot1Q 10  
 ip address 10.10.10.1 255.255.255.0  
!  
interface FastEthernet0/0.20  
 encapsulation dot1Q 20  
 ip address 10.10.20.1 255.255.255.0  
!  
interface FastEthernet0/0.30  
 encapsulation dot1Q 30  
 ip address 10.10.30.1 255.255.255.0  
!  
interface FastEthernet0/0.40  
 encapsulation dot1Q 40  
 ip address 10.10.40.1 255.255.255.0  
!  
interface FastEthernet0/0.50  
 encapsulation dot1Q 50  
 ip address 10.10.50.1 255.255.255.0  
!  
interface FastEthernet0/0.99  
 encapsulation dot1Q 99  
 ip address 10.10.99.1 255.255.255.0  
!  
interface FastEthernet0/1  
 ip address 85.143.163.237 255.255.255.0  
 ip nat outside  
 duplex auto  
 speed auto  

interface Vlan1  
 no ip address  
 shutdown  

ip nat inside source list 1 interface FastEthernet0/1 overload  
ip classless  

ip flow-export version 9  

access-list 1 permit 10.10.0.0 0.0.255.255  

line con 0  

line aux 0  

line vty 0 4  
 login  

S1:

的配置

spanning-tree mode pvst  
!  
interface FastEthernet0/1   
 switchport mode trunk  
!  
interface FastEthernet0/2  
 switchport mode trunk  
!  
interface FastEthernet0/3  
 shutdown  
!  
interface FastEthernet0/4  
 switchport mode trunk  
!  
interface FastEthernet0/5  
 shutdown  
!  
interface FastEthernet0/6  
 shutdown  
!  
interface FastEthernet0/7  
 shutdown   
!  
interface FastEthernet0/8  
 shutdown  
!  
interface FastEthernet0/9  
 shutdown  
!  
interface FastEthernet0/10  
 switchport access vlan 20  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/11   
 switchport access vlan 20  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/12  
 switchport access vlan 20  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/13  
 switchport access vlan 20  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/14  
 switchport access vlan 20  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/15  
 switchport access vlan 10  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/16  
 switchport access vlan 10  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/17  
 switchport access vlan 30  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/18  
 switchport access vlan 30  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/19  
 switchport access vlan 30  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/20  
 switchport access vlan 30  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/21  
 switchport access vlan 20  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/22  
 switchport access vlan 20  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/23  
 switchport access vlan 30  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/24  
 shutdown  
!  
interface Vlan1  
 no ip address  
 shutdown  
!  
interface Vlan99  
 ip address 10.10.99.10 255.255.255.0  
!  
ip default-gateway 10.10.99.1  

line con 0  
!  
line vty 0 4  
 login  
line vty 5 15  
 login  
!  

S2:

的配置

spanning-tree mode pvst  
!  
interface FastEthernet0/1  
 shutdown  
!  
interface FastEthernet0/2  
 switchport mode trunk  
!  
interface FastEthernet0/3  
 switchport mode trunk  
!  
interface FastEthernet0/4  
 shutdown  
!  
interface FastEthernet0/5  
 shutdown  
!  
interface FastEthernet0/6  
 shutdown  
!  
interface FastEthernet0/7  
 shutdown  
!  
interface FastEthernet0/8  
 shutdown  
!  
interface FastEthernet0/9  
 shutdown  
!  
interface FastEthernet0/10  
 switchport access vlan 40  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/11  
 switchport access vlan 40  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/12  
 switchport access vlan 40  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/13  
 switchport access vlan 40  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/14  
 switchport access vlan 40  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/15  
 switchport access vlan 40  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/16  
 shutdown  
!  
interface FastEthernet0/17  
 shutdown  
!  
interface FastEthernet0/18   
 shutdown  
!  
interface FastEthernet0/19  
 shutdown  
!  
interface FastEthernet0/20  
 shutdown  
!  
interface FastEthernet0/21  
 shutdown  
!  
interface FastEthernet0/22  
 shutdown  
!  
interface FastEthernet0/23  
 shutdown  
!  
interface FastEthernet0/24  
 shutdown  
!  
interface Vlan1  
 no ip address  
 shutdown  
!  
interface Vlan99  
 ip address 10.10.99.20 255.255.255.0  
!  
ip default-gateway 10.10.99.1  

line con 0  
!  
line vty 0 4  
 login  
line vty 5 15  
 login  
!  

S3:

的配置

spanning-tree mode pvst  
!  
interface FastEthernet0/1  
 shutdown  
!  
interface FastEthernet0/2  
 shutdown  
!  
interface FastEthernet0/3  
!  
interface FastEthernet0/4  
!  
interface FastEthernet0/5  
 shutdown  
!  
interface FastEthernet0/6  
 shutdown  
!  
interface FastEthernet0/7  
 shutdown  
!  
interface FastEthernet0/8  
 shutdown  
!  
interface FastEthernet0/9  
 shutdown  
!  
interface FastEthernet0/10  
 switchport access vlan 50  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/11  
 switchport access vlan 50  
 switchport mode access  
 spanning-tree portfast  
!  
interface FastEthernet0/12  
 shutdown  
!  
interface FastEthernet0/13  
 shutdown  
!  
interface FastEthernet0/14  
 shutdown  
!  
interface FastEthernet0/15  
 shutdown  
!  
interface FastEthernet0/16  
 shutdown  
!  
interface FastEthernet0/17  
 shutdown  
!  
interface FastEthernet0/18  
 shutdown  
!  
interface FastEthernet0/19  
 shutdown  
!  
interface FastEthernet0/20   
 shutdown  
!  
interface FastEthernet0/21  
 shutdown  
!  
interface FastEthernet0/22  
 shutdown  
!  
interface FastEthernet0/23  
 shutdown  
!  
interface FastEthernet0/24  
 shutdown  
!  
interface Vlan1  
 no ip address  
 shutdown  
!  
interface Vlan99  
 ip address 10.10.99.30 255.255.255.0  
!  
ip default-gateway 10.10.99.1  

line con 0  
!  
line vty 0 4  
 login  
line vty 5 15  
 login  
!  

Answer 1

为什么不在S3上配置主干呢？

在接口上使用description命令来描述接口连接的位置是一个非常好的主意。画上没有贴上标签，我们只能猜测。例如，S1在F0/1、F0/2和F0/4上有主干，但是哪个连接到S2，在哪个S2接口上连接？使用show cdp neighbor命令重复检查标签是否与实际连接匹配是一个好主意。

您还应该在每个交换机上创建VLAN，并将S1设置为VLAN的根开关。

Answer 2

DHCP请求失败，当终端设备未与DHCP服务器连接但到终端设备的下一个设备已启动时，将使用或配置APIPA。因此，您需要从您的下一个设备切换到DHCP /路由器，然后您将对其进行故障排除。