AR2220 DHCP方式上网,获取不了IP地址

发布时间:  2016-02-14 浏览次数:  365 下载次数:  0
问题描述

AR2220上游连接友商设备,通过DHCP方式上网,获取不了IP地址,组网拓扑如下

AR2220的相关配置
#
dhcp enable
#
interface GigabitEthernet0/0/0
 ip address dhcp-alloc
#
interface GigabitEthernet0/0/1
 ip address 192.168.1.1 255.255.255.0
#
interface GigabitEthernet0/0/2
#

处理过程

1.设备配置无问题,接口状态正常,日志告警也没有异常,但获取不到IP地址:
[Huawei]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 3
The number of interface that is DOWN in Physical is 1
The number of interface that is UP in Protocol is 2
The number of interface that is DOWN in Protocol is 2

Interface                         IP Address/Mask      Physical   Protocol 
GigabitEthernet0/0/0              unassigned           up         down     
GigabitEthernet0/0/1              192.168.1.1/24       up         up       
GigabitEthernet0/0/2              unassigned           down       down 

[Huawei]display dhcp client
DHCP client lease information on interface GigabitEthernet0/0/0 :
 Current machine state         : Requesting
 Internet address assigned via : DHCP
 Physical address              : 00e0-fc83-77cc

2.抓包查看AR2220与上游设备的DHCP报文交互过程:


通过抓包可以发现上游设备自动分配的IP地址和AR2220的GE0/0/1接口的IP地址在同一网段,存在冲突,于是设备在获取到地址后发送了DHCP Release报文主释了获取到的地址。


3.修改AR2220 GE0/0/1接口的网段后解决。

根因

上游设备自动分配的IP地址和本端设备GE0/0/1接口的IP地址网段冲突造成。

解决方案

修改AR2220 GE0/0/1接口的网段后解决。

END