Damp Interface Transitions

By default, when an interface changes from being up to being down, or from down to up, this transition is advertised immediately to the router software and hardware. In some situations, for example, when an interface is connected to an ADM or WDM, or to protect against SONET framer holes, you might want to damp interface transitions, thereby not advertising the interface's transition until a certain period of time has passed, called the hold-time. When you have damped interface transitions and the interface goes from up to down, the interface is not advertised to the rest of the system as being down until it has remained down for the hold-time period. Similarly when an interface goes from down to up, it is not advertised as being up until it has remained up for the hold-time period.

To damp interface transitions, include the hold-time statement at the [edit interfaces interface-name] hierarchy level:

[edit interfaces interface-name] 

hold-time up milliseconds down milliseconds; 

The time can be a value from 0 through 65,534 milliseconds. Upon execution, the time value that you specify is rounded up to the nearest whole second; therefore, we recommend that you configure the up and down options to multiples of 1000. The default value is 0, which means that interface transitions are not damped.