设备运行过程中终端和接入交换机突然无法通过DHCP获取地址

现场反馈，设备运行过程中突然无法通过DHCP获取地址

5130---6520---7560

DHCP服务器配置在7560上，5130下接终端和AP，中间6520二层透传。

通过DHCP方式的流统，发现报文是丢在了5130上联6520的聚合口上，即从终端或AP收到的DHCP请求报文没有从5130的上联口发出去。

[2#-2F-OFFICE-POE-SW-a.a.a.a]dis qos policy interface inbound

Interface: GigabitEthernet1/0/19

  Direction: Inbound

  Policy: dhcp-c

   Classifier: dhcp-c

     Operator: AND

     Rule(s) :

      If-match acl 3010

      If-match source-mac xxxx-xxxx-xxxx  //测试终端mac

     Behavior: dhcp-c

      Accounting enable:

        18 (Packets)

Interface: Ten-GigabitEthernet1/0/27

  Direction: Inbound

  Policy: dhcp-s

   Classifier: dhcp-s

     Operator: AND

     Rule(s) :

      If-match acl 3011

      If-match source-mac yyyy-yyyy-yyyy

      If-match destination-mac xxxx-xxxx-xxxx

     Behavior: dhcp-s

      Accounting enable:

        0 (Packets)

Interface: Ten-GigabitEthernet1/0/28

  Direction: Inbound

  Policy: dhcp-s

   Classifier: dhcp-s

     Operator: AND

     Rule(s) :

      If-match acl 3011

      If-match source-mac yyyy-yyyy-yyyy

      If-match destination-mac xxxx-xxxx-xxxx

     Behavior: dhcp-s

      Accounting enable:

        0 (Packets)

[2#-2F-OFFICE-POE-SW-a.a.a.a]dis qos policy interface out

[2#-2F-OFFICE-POE-SW-a.a.a.a]dis qos policy interface outbound

Interface: GigabitEthernet1/0/19

  Direction: Outbound

  Policy: dhcp-s

   Classifier: dhcp-s

     Operator: AND

     Rule(s) :

      If-match acl 3011

      If-match source-mac yyyy-yyyy-yyyy

      If-match destination-mac xxxx-xxxx-xxxx

     Behavior: dhcp-s

      Accounting enable:

        0 (Packets)

Interface: Ten-GigabitEthernet1/0/27

  Direction: Outbound

  Policy: dhcp-c

  Classifier: dhcp-c

     Operator: AND

     Rule(s) :

      If-match acl 3010

      If-match source-mac xxxx-xxxx-xxxx

     Behavior: dhcp-c

      Accounting enable:

        0 (Packets)

Interface: Ten-GigabitEthernet1/0/28

  Direction: Outbound

  Policy: dhcp-c

   Classifier: dhcp-c

     Operator: AND

     Rule(s) :

      If-match acl 3010

      If-match source-mac xxxx-xxxx-xxxx

     Behavior: dhcp-c

      Accounting enable:

        0 (Packets)

在5130配置业务接口同样无法自动获取地址，手工配置地址可以和DHCP网关互通。

设备全局使能了dhcp snooping enable，上行朝向dhcp server的接口bagg1下没有配置为信任端口，因此转发不出去dhcp请求报文；另外，开启了dhcp snooping功能后，dhcp报文会上cpu处理，因此出方向统计不到；

至于为什么之前获取地址正常，后续又不能获取了；

沟通得知，bagg1聚合口是最近才加上去的，终端之前拿地址应该是在只用单根线的时候拿到的，等到地址最后老化超时了，再申请、设备bagg1有没有配置为信任端口，也就拿不到了；

将bagg1上配置为信任端口，问题已经解决；

将bagg1上配置为信任端口，问题已经解决；