R0106-HP MSR Router Series High Availability Configuration Guide(V7)

4
Interface backup configuration task list
Task Remarks
Configuring strict active/standby interface backup:
• (Method 1.) Explicitly specifying backup interfaces
without traffic thresholds
• (Method 2.) Using interface backup with the Track
module
You cannot use these two methods at the same time
for a primary interface and its backup interfaces.
Use method 1 if you want to monitor the interface
state of the primary interface for a switchover to
occur.
Use method 2 if you want to monitor any other
state, such as the link state of the primary interface.
Configuring load-shared interface backup
A primary interface and its backup interfaces
operate in load sharing mode after you specify the
traffic thresholds on the primary interface.
This method cannot be used with the other two
methods at the same time for an interface.
Configuring strict active/standby interface backup
You can use one of the following methods to configure strict active/standby interface backup:
• Explicitly specify backup interfaces for a primary interface. If this method is used, interface backup
monitors the interface state of the primary interface. Activation and deactivation of a backup
interface depends on the interface state change of the primary interface.
• Use interface backup with the Track module. If this method is used, interface backup uses a track
entry to monitor the link state of the primary interface. Activation and deactivation of a backup
interface depends on the link state change of the primary interface.
Explicitly specifying backup interfaces without traffic thresholds
For the primary and backup interfaces to operate in strict active/standby mode, do not specify the traffic
thresholds on the primary interface. If the traffic thresholds are configured, the interfaces will operate in
load sharing mode.
You can assign priority to backup interfaces. When the primary interface fails, the backup interfaces are
activated in descending order of priority, with the highest-priority interface activated first. If two backup
interfaces have the same priority, the one configured first has preference.
To prevent link flapping from causing frequent interface switchovers, you can configure the following
switchover delay timers:
• Up delay timer—Number of seconds that the primary or backup interface must wait before it can
come up.
• Down delay timer—Number of seconds that the active primary or backup interface must wait
before it is set to down state.
When the link of the active interface fails, the interface state does not change immediately. Instead, a
down delay timer starts. If the link recovers before the timer expires, the interface state does not change.
If the link is still down when the timer expires, the interface state changes to down.
To configure strict active/standby interface backup for a primary interface: