Configuring load-shared interface backup
To implement load-balanced interface backup, you must configure the traffic thresholds on the primary interface. Interface backup regularly compares the amount of traffic with the thresholds to determine whether to activate or deactivate a backup interface. The traffic polling interval is user configurable.
You can assign priority to backup interfaces.
When the amount of traffic on the primary interface exceeds the upper threshold, the backup interfaces are activated in descending order of priority.
When the total amount of traffic on all load-shared interfaces decreases below the lower threshold, the backup interfaces are deactivated in ascending order of priority.
If two backup interfaces have the same priority, the one configured first has preference.
If a traffic flow has a fast forwarding entry, all packets of the flow will be forwarded out of the outgoing interface in the entry. The packets of the flow will not be distributed between interfaces when the upper threshold is reached. For more information about fast forwarding, see Layer 3—IP Services Configuration Guide.
To configure load-shared backup for an interface:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter interface view. | interface interface-type interface-number | You must enter the view of the primary interface. |
3. Configure a backup interface for the interface. | backup interface interface-type interface-number [ priority ] | By default, an interface does not have any backup interfaces. Repeat this command to specify up to three backup interfaces. |
4. Set backup load sharing thresholds. | backup threshold upper-threshold lower-threshold | By default, no traffic thresholds are configured. |
5. Set the traffic polling interval. | backup timer flow-check interval | The default interval is 30 seconds. |