IOS

Cisco IOS Software, C3750E Software (C3750E-UNIVERSALK9-M), Version 12.2(55)SE5, RELEASE SOFTWARE (fc1)

故障现象：
故障接口插不插网线指示灯都为 桔红色，查看接口状态为

#sh interfaces status
Port      Name               Status       Vlan       Duplex  Speed Type
Gi1/0/48                     err-disabled 1            auto   auto 10/100/1000BaseTX

原因查找：

查看err-disable原因
#show interface status err-disable

Port      Name               Status       Reason               Err-disabled Vlans
Gi1/0/48                     err-disabled loopback

loopback，看来是环路了

#看看具体配置

#查看针对哪些功能开启了err检测
#sh errdisable detect 
ErrDisable Reason            Detection    Mode
-----------------            ---------    ----
arp-inspection               Enabled      port
bpduguard                    Enabled      port
channel-misconfig (STP)      Enabled      port
community-limit              Enabled      port
dhcp-rate-limit              Enabled      port
dtp-flap                     Enabled      port
gbic-invalid                 Enabled      port
inline-power                 Enabled      port
invalid-policy               Enabled      port
l2ptguard                    Enabled      port
link-flap                    Enabled      port
loopback                     Enabled      port
lsgroup                      Enabled      port
mac-limit                    Enabled      port
pagp-flap                    Enabled      port
port-mode-failure            Enabled      port
pppoe-ia-rate-limit          Enabled      port
psecure-violation            Enabled      port/vlan
security-violation           Enabled      port
sfp-config-mismatch          Enabled      port
small-frame                  Enabled      port
storm-control                Enabled      port
udld                         Enabled      port
vmps                         Enabled      port

#检测到err后是否重启接口，重启接口的间隔时间是多少
#sh errdisable recovery
ErrDisable Reason            Timer Status
-----------------            --------------
arp-inspection               Disabled
bpduguard                    Disabled
channel-misconfig (STP)      Disabled
dhcp-rate-limit              Disabled
dtp-flap                     Disabled
gbic-invalid                 Disabled
inline-power                 Disabled
l2ptguard                    Disabled
link-flap                    Disabled
mac-limit                    Disabled
loopback                     Disabled
pagp-flap                    Disabled
port-mode-failure            Disabled
pppoe-ia-rate-limit          Disabled
psecure-violation            Disabled
security-violation           Disabled
sfp-config-mismatch          Disabled
small-frame                  Disabled
storm-control                Disabled
udld                         Disabled
vmps                         Disabled

Timer interval: 300 seconds

Interfaces that will be enabled at the next timeout:

恢复接口：

#关闭再打开接口就行了
#interface Gi1/0/48
#shutdown 
#no shutdown