Configuring physical state change suppression on an Ethernet interface
![[IMPORTANT: ]](images/important.png) | IMPORTANT: Do not configure physical state change suppression on an Ethernet interface that has RRPP, spanning tree protocols, or Smart Link enabled. | |
The physical link state of an Ethernet interface is either up or down. Each time the physical link of a port comes up or goes down, the interface immediately reports the change to the CPU. The CPU then performs the following operations:
Notifies the upper-layer protocol modules (such as routing and forwarding modules) of the change for guiding packet forwarding.
Automatically generates traps and logs, informing the user to take the correct actions.
To prevent frequent physical link flapping from affecting system performance, configure physical state change suppression to suppress the reporting of physical link state changes. The system reports physical layer changes only when the suppression interval expires.
When the link-delay delay-time command is configured:
The link-down event is not reported to the CPU unless the interface is still down when the suppression interval (delay-time) expires.
The link-up event is immediately reported.
When the link-delay delay-time mode up command is configured:
The link-up event is not reported to the CPU unless the interface is still up when the suppression interval (delay-time) expires.
The link-down event is immediately reported.
When the link-delay delay-time mode updown command is configured:
The link-down event is not reported to the CPU unless the interface is still down when the suppression interval (delay-time) expires.
The link-up event is not reported to the CPU unless the interface is still up when the suppression interval (delay-time) expires.
To configure physical state change suppression on an Ethernet interface:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter Ethernet interface view. | interface interface-type interface-number | N/A |
3. Configure physical state change suppression on the interface. | link-delay [ msec ] delay-time [ mode { up | updown }] | By default, the link-down or link-up event is immediately reported to the CPU. If you configure this command multiple times on an Ethernet interface, the most recent configuration takes effect. |