Creating A Dynamic Route Backup Group; Assigning A Dialup Interface To A Dynamic Route Backup Group - HP MSR Router Series Wan Access Configuration Manual

2. If a minimum of one valid route exists with an egress interface that is not assigned to the dynamic
route backup group, the primary link is considered as up.
3. If no valid route exists, the primary link is considered as down and unusable. Then DDR creates a
backup 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 backup link can be brought down either immediately or when
the timer expires, 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 activated.
•
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 dialup link as the backup. When establishing the
backup link, DDR checks the dialer route commands configured on the backup interface. Then, it
establishes the backup link by using the dialer route command first configured for the monitored
networks. Only one backup link is established.
To create a dynamic route backup group:
Step
1. Enter system view.
2. Create a dynamic route
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 as a backup interface, 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:
Command
system-view
standby routing-group
group-number rule ip ip-address
{ mask | mask-length }
[ vpn-instance vpn-instance-name ]
191
Remarks
N/A
By default, no dynamic route
backup group is created.
The IP address and VPN instance
specified in the standby
routing-group rule command must
be the same as those specified in
the dialer route command.