Method of Configuring Interfaces in ERROR DOWN State to Automatically Restore to the Up State

Publication Date:  2016-02-01 Views:  1549 Downloads:  0
Issue Description
An interface is in ERROR DOWN state, it cannot receive or send packets, and its indicator is off. The switch generates the ERROR-DOWN_1. hwErrordown alarm.
Handling Process
If a large number of interfaces in ERROR DOWN state need to be recovered, manual recovery is time consuming and some interfaces may be omitted. To prevent this problem, you can configure interfaces in ERROR DOWN state to automatically restore to the Up state, and set the recovery delay. The configuration procedure is as follows:

1. Run the system-view command to enter the system view.

2. Run the error-down auto-recovery cause { auto-defend | bpdu-protection | crc-statistics | dual-active | fabric-uplink-threshold | leaf-mstp | link-flap | loopback-detect | m-lag | mac-address-flapping | no-stack-link | portsec-reachedlimit | stack-config-conflict | stack-member-exceed-limit | storm-control | transceiver-power-low } interval interval-value command to configure the recovery delay after which interfaces in ERROR DOWN state automatically restore to the Up state. The value ranges from 30 to 86400, in seconds.

3. Run the display error-down recovery command to view information about interfaces in ERROR DOWN state, including the interface name, cause of the Error-Down event, recovery delay, and remaining time.
Root Cause
The Error-Down mechanism is a protection mechanism provided by CE series switches and involves multiple features including interface, stacking, super virtual fabric (SVF), and security. If any of these features is configured on an interface and the switch detects that the interface or relevant service fails, the switch shuts down the interface and sets the interface status to ERROR DOWN to prevent the fault from affecting the entire network.

You can run the display interface command to view the cause of the interface Error-Down event.

<HUAWEI> display interface 10ge 1/0/1
10GE1/0/1 current state : ERROR DOWN(link-flap) (ifindex: 5)         
Line protocol current state : DOWN                                   
Switch Port, PVID :    1, TPID : 8100(Hex), The Maximum Frame Length is 9216    
Internet protocol processing : disabled                              
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 306b-2079-2201 
Port Mode:  COMMON COPPER,     Port Split:                         - 
Speed:               AUTO,     Loopback:                        NONE 
Duplex:              FULL,     Negotiation:                   ENABLE 
Mdi:                 AUTO,     Flow-control:                 DISABLE 
  ---- More ----

As shown in the preceding command output, link flapping is the cause of the Error-Down event on 10GE1/0/1. The switch detects that 10GE1/0/1 has frequently alternated between Up and Down states, shuts down the interface, and sets the interface status to ERROR DOWN(link-flap).
1. The automatic recovery measure is ineffective for interfaces in ERROR DOWN state. Therefore, you are advised to configure the automatic recovery measure when configuring services on interfaces.

2. You need a period of time to rectify service faults after an interface transits to the ERROR DOWN state. Therefore, you are advised to set the recovery delay to a long time, for example, 1 hour.