Deployment Guide

ICMP redirects are not sent
ICMP unreachables are not sent
IP unicast RPF check is not supported
Automatic recovery of an Err-disabled interface
The Dell EMC Networking OS attempts to recover the interface from the Err-disabled state automatically based on the cause of
the error.
You can configure the Dell EMC Networking OS to recover an interface from Err-disabled state automatically, if the interface is
changed to Err-disabled state due to the following:
● BPDU Guard
● FEFD
● MAC learning limit
● ARP inspection
Based on the automatic recovery configuration, when the interface is changed to Err-disabled state, the Dell EMC Networking
OS invokes a timer for the configured time-out interval. Upon expiration of the timer, the interface is moved to operationally up
state if the encountered error is fixed. 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.
Configuring an automatic recovery for an Err-disabled interface
To configure automatic Err-disabled recovery of an interface and time-out interval, use the following commands.
1. Configure 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 configured before the interface moves to Err-disabled state. If not, the recovery action
is not performed.
2. Configure 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 flap 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.
378 Interfaces