Exam 300-115 | Question id=1321 | Layer 2 Technologies |
While working in the core network building, a technician accidently bumps the fiber connection between two core switches and damages one of the pairs of fiber. As designed, the link was placed into a non-forwarding state due to a fault with UDLD. After the damaged cable was replaced, the link did not recover. What solution allows the network switch to automatically recover from such an issue?
A. |
macros | |
B. |
errdisable autorecovery | |
C. |
IP Event Dampening | |
D. |
command aliases | |
E. |
Bidirectional Forwarding Detection |
There are a number of events which can disable a link on a Catalyst switch, such as the detection of a loopback, UDLD failure, or a broadcast storm. By default, manual intervention by an administrator is necessary to restore the interface to working order; this can be done by issuing shutdown followed by no shutdown on the interface. The idea behind requiring administrative action is so that a human engineer can intercede, assess, and (ideally) correct the issue. However, some configurations may be prone to accidental violations, and a steady recurrence of these can amount to a huge time sink for the administrative staff.
This is where errdisable autorecovery can be of great assistance. We can configure the switch to automatically re-enable any error-disabled interfaces after a specified timeout period. This gives the offending issue a chance to be cleared by the user (for example, by removing an unapproved device) without the need for administrative intervention.