Creating A Dynamic Route Backup Group; Assigning A Dialup Interface To A Dynamic Route Backup Group - HPE FlexNetwork MSR series Configuration Manual

To use this feature, you must create a dynamic route backup group and define a network to be
monitored. When a dialup interface is assigned to the dynamic route backup group, the system
monitors the routes by using the following process:
1. The system identifies whether a minimum of one valid route exists to the monitored network.
2. If a minimum of one valid route exists with an egress interface outside the dynamic route
backup group, the system determines that the primary link is up.
3. If no valid route exists, the system determines that the primary link is down and unusable. Then,
DDR creates a secondary link on the backup interface to forward traffic. During this process, the
system periodically checks the primary link status.
4. When the primary link recovers, the secondary link can be brought down either immediately or
after the secondary link disconnection delay, depending on the configuration.
Some routing protocols (such as BGP) use the optimal routes by default. In a BGP network, when
the secondary link is activated because the primary link fails, the device will learn a route to the
monitored network through BGP. When the primary link recovers, the device will also learn a route to
the monitored network through BGP. However, the route learned for the primary link might be less
optimal than that learned for the secondary link. As a result, the following events occur:
•
The route learned for the secondary link remains active.
•
Dynamic route monitoring fails.
•
The switchover from secondary link to primary link fails.
To solve this problem, configure the router to prefer the route learned for the primary link when the
primary and secondary links are both active.

Creating a dynamic route backup group

A dynamic route backup group can define multiple networks to be monitored. When no valid route
exists to any of the monitored networks, DDR creates a secondary link. When establishing the
secondary link, DDR checks for the dialer route commands configured for the monitored networks
on the backup interface. Then, it establishes the secondary link by using the dialer route command
first configured for the monitored networks. Only one secondary link can be established.
To create a dynamic route backup group:
Step
1. Enter system view.
2. Create
backup group, and add a
network to be monitored to
the group.

Assigning a dialup interface to a dynamic route backup group

Before assigning a dialup interface to a dynamic route backup group, make sure DDR is enabled on
the interface. A dialup interface can be assigned to multiple dynamic route backup groups.
To assign a dialup interface to a dynamic route backup group:
Step
1. Enter system view.
Command
system-view
standby
a dynamic route
group-number rule ip ip-address
{
[
vpn-instance-name ]
Command
system-view
routing-group
mask | mask-length
vpn-instance
183
Remarks
N/A
By default, no dynamic route
backup group is created.
The IP address and VPN instance
specified in the
}
routing-group rule
must be the same as those
specified in the dialer route
command.
Remarks
N/A
standby
command