Taming the Err-Disable Trap: How to Recover Errdisabled-Disabled Ports on Cisco Switches

How to Monitor the Status of an Errdisabled Port by Using the Show Errdisable Recovery Command

The show errdisable recovery command is a command that will display information about the errdisable recovery feature running on the switch. This command can help us find out what error conditions this feature can handle, the wait time before the switch reactivates the errdisabled port, and the recovery status of the errdisabled port. The following is an example output of this command:

Switch# show errdisable recovery
ErrDisable Reason            Timer Status
-----------------            --------------
link-flap                    Enabled
bpduguard                    Enabled
psecure-violation            Enabled
udld                         Enabled
channel-misconfig            Enabled

Timer interval: 300 seconds

Interfaces that will be enabled at the next timeout:

Interface       Errdisable reason      Time left(sec)
---------       -----------------      --------------
Gi1/0/1         link-flap              120
Gi1/0/2         bpduguard              180
Gi1/0/3         psecure-violation      240
Gi1/0/4         udld                   300
Gi1/0/5         channel-misconfig      300

From the output above, we can see that the errdisable recovery feature is enabled for the five most common error conditions, namely link flapping, STP violation, Port Security violation, UDLD violation, and EtherChannel misconfiguration. In addition, we can also see that the wait time before the switch re-enables the errdisabled port is 300 seconds, and the recovery status of the errdisabled port, including the time remaining before the port is reactivated.

Using the above commands, we can monitor the status of the errdisabled port and the errdisable recovery feature running on the switch.

Conclusion

An errdisabled port is a port that has been disabled by the Cisco switch because an error condition is detected. Errdisabled ports can cause serious network interference, especially if they are connected to critical devices such as servers, routers, or end devices. Therefore, it is important to know how to address errdisabled ports and prevent them from happening in the future.

By understanding and applying the concepts we’ve learned, we can better manage errdisabled ports and improve the performance and reliability of our network.

Latest Articles