Concept Guide

ARP inspection
Based on the automatic recovery conguration, when the interface is changed to Err-disabled state, the Dell EMC Networking OS invokes
a timer for the congured time-out interval. Upon expiration of the timer, the interface is moved to operationally up state if the encountered
error is xed. If not, the interface is again moved to Err-disabled state again.
Dell EMC Networking OS generates syslog message for Err-disabled recovery when:
The timer is started for recovery of an interface
The recovery action is complete
Following is the sample syslog displayed when the timer for Err-disable recovery is started:
May 8 17:18:57 %STKUNIT1-M:CP %IFMGR-5-ERR_DIS_RECOVERY_TIMER_START: 180 seconds timer started
to attempt recovery of interface Gi 2/18 from error disabled state caused by bpdu-guard.
Following is the sample syslog displayed when the recovery action is complete:
May 8 17:21:57 %STKUNIT1-M:CP %IFMGR-5-ERR_DIS_RECOVERY_COMPLETE: Error Disable Recovery timer
expired for interface Gi 2/18.
Conguring an automatic recovery for an Err-disabled
interface
To congure automatic Err-disabled recovery of an interface and time-out interval, use the following commands.
1 Congure automatic recovery of an interface from Err-disabled state based on the cause.
CONFIGURATION mode
errdisable recovery cause {bpduguard | fefd | maclearnlimit | arp-insection}
NOTE
: This command has to be congured before the interface moves to Err-disabled state. If not, the recovery action is
not performed.
2 Congure the recovery time-out interval. You can enter the interval from the range of 30 to 86,400 seconds. The default is 300
seconds.
CONFIGURATION mode
errdisable recovery interval seconds
NOTE
: In Dell EMC Networking OS, for optimal performance of FEFD, the best practice is to set the error disable recover
timer not exceeding 30 seconds with FEFD interval set to default. Thus, avoiding any potential interface ap and
overlapping of recovery timings causing the FEFD enabled interface to stay in error-disabled state for a longer interval.
However, this timer value need to be applied only if the FEFD error-disable mode is set to aggressive mode.
Whenever the Err-disable recovery timer is recongured, it will get eective only after the current timer expires. Following message is
displayed after each Err-disable recovery timer conguration:
DellEMC(conf)# errdisable recovery interval 30
New timer interval will be effective from the next timer instance only.
Example conguration for the recovery cause and the timer interval
Following is the sample steps to congure the recovery cause and the timer interval for automatic recovery of an interface.
DellEMC# configure termimal
DellEMC(conf)# errdisable recovery cause fefd
DellEMC(conf)# errdisable recovery interval 30
DellEMC(conf)#
Interfaces
425