局域网上网慢（环路）

1、现象

局域网的用户上网慢；

2、处理过程

1）局域网出口链路查看无问题；

2）查看核心交换机的日志

*Jun 19 10:19:43: %NFPP_ARP_GUARD-4-DOS_DETECTED: Host was detected.(2015-6-19 10:19:43)

*Jun 19 10:53:44: %NFPP_ARP_GUARD-4-DOS_DETECTED: Host was detected.(2015-6-19 10:19:44)

*Jun 19 10:54:14: %NFPP_ARP_GUARD-4-DOS_DETECTED: Host was detected.(2015-6-19 10:19:44)

*Jun 19 10:54:44: %NFPP_ARP_GUARD-4-DOS_DETECTED: Host was detected.(2015-6-19 10:19:44)

*Jun 19 10:55:14: %NFPP_ARP_GUARD-4-DOS_DETECTED: Host was detected.(2015-6-19 10:19:44)

*Jun 19 10:55:44: %NFPP_ARP_GUARD-4-DOS_DETECTED: Host was detected.(2015-6-19 10:19:44)

初步判断是环路问题。

3）通过在交换机配置开启环路检测命令，发现

*Jun 19 10:55:01: %PORT_SECURITY-4-ERR_RECOVER: Interface GigabitEthernet 0/22 recover from an error.

*Jun 19 10:55:01: %RLDP-3-LINK_DETECT_RECOVER: rldp recover interface GigabitEthernet 0/22 from loop error

*Jun 19 10:55:03: %LINK-3-UPDOWN: Interface GigabitEthernet 0/22, changed state

to up.

*Jun 19 10:55:03: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet 0/22, changed state to up.

*Jun 19 10:55:03: %RLDP-3-LINK_DETECT_ERROR: loop detection error detect on interface GigabitEthernet 0/24.set this interface errordisable!

*Jun 19 10:55:05: %LINK-3-UPDOWN: Interface GigabitEthernet 0/24, changed stateto down.

*Jun 19 10:55:05: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEtherne

t 0/24, changed state to down.

 发现在GigabitEthernet 0/22和GigabitEthernet 0/24端口下存在环路问题，具体处理一下该端口下的问题。