To define how much time should elapse before a secondary line status changes after a primary line status has changed, use the backup delay command in interface configuration mode. To return to the default so that as soon as the primary fails, the secondary is immediately brought up without delay, use the no form of this command.

backup delay {enable-delay-period | never} {disable-delay-period | never}

no backup delay {enable-delay-period | never} {disable-delay-period | never}

Syntax Description

enable-delay-period Number of seconds that elapse after the primary line goes down before the Cisco IOS software activates the secondary line.
disable-delay-period Number of seconds that elapse after the primary line comes up before the Cisco IOS software deactivates the secondary line.
never Secondary line is never activated or deactivated.

Command Default

0 second delay

Command Modes

Interface configuration

Command History

Release Modification
10.0 This command was introduced.
12.2(33)SRB1 This command was integrated into Cisco IOS Release 12.2(33)SRB1.

Usage Guidelines

For environments in which spurious signal disruptions appear as intermittent lost carrier signals, we recommend that you enable some delay before activating and deactivating a secondary line.

For the Cisco 7600 Backup Interface for Flexible UNI feature to work correctly, the enable and disable backup delay must be 0.


The following example sets a 10-second delay on deactivating the secondary line (serial interface 0); however, the line is activated immediately.

interface serial 0
 backup delay 0 10

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