Ovs交换机环路

现象：node3节点挂了，从node4 ssh上去 ping不通网关192.168.19.254。
解决办法：现在通过串口minicom登录交换机，利用内置的安全保护机制阻止网络风暴。

1. 先查看网桥是否正确连接

node3：$ ovs-vsctl show：

1. br-in
   
2. br-out
   

2. minicom登录交换机并enable

Switch#show loggingSyslog logging: enabled (0 messages dropped, 0 messages rate-limited, 0 flushes)No Active Message Discriminator.No Inactive Message Discriminator.    Console logging: level debugging, 63 messages logged, xml disabled,                     filtering disabled    Monitor logging: level debugging, 0 messages logged, xml disabled,                     filtering disabled    Buffer logging:  level debugging, 63 messages logged, xml disabled,                    filtering disabled    Exception Logging: size (4096 bytes)    Count and timestamp logging messages: disabled    File logging: disabled    Persistent logging: disabledNo active filter modules.    Trap logging: level informational, 66 message lines logged        Logging Source-Interface:       VRF Name:Log Buffer (4096 bytes):hanged state to upMar 30 01:28:15.449: %LINK-3-UPDOWN: Interface GigabitEthernet0/10, changed stapMar 30 01:28:15.449: %LINK-3-UPDOWN: Interface GigabitEthernet0/12, changed stapMar 30 01:28:15.486: %LINK-3-UPDOWN: Interface GigabitEthernet0/14, changed stapMar 30 01:28:15.486: %LINK-3-UPDOWN: Interface GigabitEthernet0/15, changed stapMar 30 01:28:15.544: %LINK-3-UPDOWN: Interface GigabitEthernet0/19, changed stapMar 30 01:28:15.565: %LINK-3-UPDOWN: Interface GigabitEthernet0/2, changed statpMar 30 01:28:15.570: %LINK-3-UPDOWN: Interface GigabitEthernet0/6, changed statpMar 30 01:28:15.607: %LINK-3-UPDOWN: Interface GigabitEthernet0/13, changed stapMar 30 01:28:15.607: %LINK-3-UPDOWN: Interface GigabitEthernet0/16, changed stapMar 30 01:28:15.643: %LINK-3-UPDOWN: Interface GigabitEthernet0/9, changed statpMar 30 01:28:15.643: %LINK-3-UPDOWN: Interface GigabitEthernet0/24, changed stapMar 30 01:28:15.816: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthnMar 30 01:28:16.451: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.451: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.482: %LINK-3-UPDOWN: Interface GigabitEthernet0/11, changed stapMar 30 01:28:16.487: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.487: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.545: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.566: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.571: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.608: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.608: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.645: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.645: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:16.723: %LINK-3-UPDOWN: Interface GigabitEthernet0/17, changed stapMar 30 01:28:16.723: %LINK-3-UPDOWN: Interface GigabitEthernet0/18, changed stapMar 30 01:28:16.765: %LINK-3-UPDOWN: Interface GigabitEthernet0/20, changed stapMar 30 01:28:17.484: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:17.725: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:17.725: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:17.767: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:21.772: %PKI-6-AUTOSAVE: Running configuration saved to NVRAMMar 30 01:28:24.986: %LINK-3-UPDOWN: Interface GigabitEthernet0/7, changed statpMar 30 01:28:25.988: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:37.218: %LINK-3-UPDOWN: Interface GigabitEthernet0/22, changed stapMar 30 01:28:38.219: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthpMar 30 01:28:42.193: %DTP-5-DOMAINMISMATCH: Unable to perform trunk negotiation.Mar 30 02:18:10.717: %ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected on Gigab.Mar 30 02:18:10.717: %PM-4-ERR_DISABLE: loopback error detected on Gi0/19, putteMar 30 02:18:11.724: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthnMar 30 02:18:12.730: %LINK-3-UPDOWN: Interface GigabitEthernet0/19, changed stanSwitch#Switch#Switch#Switch#configureConfiguring from terminal, memory, or network [terminal]? Enter configuration commands, one per line.  End with CNTL/Z.Switch(config)#errdisable recovery cause loopbackSwitch(config)#eixt                ^% Invalid input detected at '^' marker.Switch(config)#show errdisable recovery                 ^% Invalid input detected at '^' marker.Switch(config)#show errdisable recovery                 ^% Invalid input detected at '^' marker.Switch(config)#exitSwitch#Mar 30 02:59:05.434: %SYS-5-CONFIG_I: Configured from console by consoleshow % Type "show ?" for a list of subcommandsSwitch#Switch#show errdisable recoveryErrDisable Reason            Timer Status-----------------            --------------bpduguard                    Disabledchannel-misconfig (STP)      Disableddhcp-rate-limit              Disableddtp-flap                     Disabledgbic-invalid                 Disabledinline-power                 Disabledlink-flap                    Disabledmac-limit                    Disabledloopback                     Enabledpagp-flap                    Disabledport-mode-failure            Disabledpppoe-ia-rate-limit          Disabledpsecure-violation            Disabledsecurity-violation           Disabledsfp-config-mismatch          Disabledsmall-frame                  Disabledstorm-control                Disabledudld                         Disabledvmps                         Disabledpsp                          DisabledTimer interval: 300 secondsInterfaces that will be enabled at the next timeout:Interface       Errdisable reason       Time left(sec)---------       -----------------       --------------Gi0/19                  loopback          264Switch#Switch#Switch#Switch#Switch#Switch#Switch#Switch#Switch#Switch#Switch#Switch#Switch#show errdisable recovery