3.4. Configuring Interface Errdisable

Overview

Function Introduction

Errdisable is a mechanism to protect the system through shutdown the abnormal interface. If an interface enters errdisable state, there are two ways to recovery it from errdisabled state. The first one is to enable errdisable recovery of this reason before errdisable detection; the interface will be recovered automatically after the configured time. But if errdisable occurred first, then errdisable recovery is enabled, the errdisable will not be recovered automatically. The secondary one is configuring “no shutdown” command on the errdisabled interface.

The flap of interface link state is a potential error caused by hardware or line problem. The administrator can also configure the detection conditions of interface link flap to suppress the flap.

Principle Description

N/A

Configuration

Configuring Errdisable Detection

step 1 Enter the configure mode

Switch# configure terminal

step 3 Exit the configure mode

Switch(config)# end

step 4 Validation

Use the following command to display the configuration of error disable:

Switch# show errdisable detect
ErrDisable Reason Detection status
----------------- ----------------
bpduguard Enabled
bpduloop Enabled
link-monitor-failure Enabled
oam-remote-failure Enabled
port-security Enabled
link-flap Enabled
monitor-link Enabled
udld Disabled
fdb-loop Disabled
loopback-detection Enabled
reload-delay Enabled

Configuring Errdisable Recovery

step 1 Enter the configure mode

Switch# configure terminal

step 2 Enable errdisable and set recovery interval

Switch(config)# errdisable recovery reason link-flap
Switch(config)# errdisable recovery interval 30

step 3 Exit the configure mode

Switch(config)# end

step 4 Validation

Use the following command to display the configuration of error disable recovery:

Switch# show errdisable recovery
ErrDisable Reason Timer Status
 -------- ------- ----- ------
bpduguard Disabled
bpduloop Disabled
link-monitor-failure Disabled
oam-remote-failure Disabled
port-security Disabled
link-flap Enabled
udld Disabled
fdb-loop Disabled
loopback-detection Disabled
Timer interval: 30 seconds

Checking Errdisable Status

Administrator can check the interface errdisable status though two commands.

Case 1 Enable errdisable recovery

If link flap errdisable is enabled recovery, the command will display the left time for recovery; Otherwise, will display “unrecovery”.

Switch# show errdisable recovery
ErrDisable Reason Timer Status
----------------- --------------
bpduguard Disabled
bpduloop Disabled
link-monitor-failure Disabled
oam-remote-failure Disabled
port-security Disabled
link-flap Enabled
udld Disabled
fdb-loop Disabled
loopback-detection Disabled
Timer interval: 300 seconds
Interfaces that will be enabled at the next timeout:
Interface Errdisable Reason Time Left(sec)
--------- ----------------- --------------
eth-0-3 link-flap 25

Case 2 Disalbe errdisable recovery

Switch# show errdisable recovery
ErrDisable Reason Timer Status
----------------- --------------
bpduguard Disabled
bpduloop Disabled
link-monitor-failure Disabled
oam-remote-failure Disabled
port-security Disabled
link-flap Disabled
udld Disabled
fdb-loop Disabled
loopback-detection Disabled
Timer interval: 300 seconds

case 3 Display interface brief information to check errdisable state.

Switch# show interface status
Port Status Duplex Speed Mode Type Description
-----------------------------------------------------------------------------
eth-0-1 up a-full a-1000 TRUNK 1000BASE_SX
eth-0-2 down auto auto TRUNK Unknown
eth-0-3 errdisable a-full a-1000 TRUNK 1000BASE_SX
eth-0-4 down auto auto ACCESS Unknown

Application cases

N/A