auto-frr (BGP-IPv4 unicast address family view)

Usage Scenario

As networks continue to develop, services, such as voice, online video, and financial services, pose higher requirements for real-time transmission. Primary and backup links are typically deployed on a network to ensure the stability of these services. In traditional forwarding mode, when multiple routes to the same destination are available, the selects the optimal route and delivers the route to the FIB table to guide data forwarding. If the optimal route fails, the device must wait for route convergence to be completed, after which the device reselects an optimal route and delivers it to the FIB table to restore services. This process leads to long service interruption, resulting in a failure to meet service requirements.

After BGP Auto FRR is enabled on a router, the router selects the optimal route from the routes that are bound for the same destination network. In addition, the router automatically adds information about the second optimal route to the backup forwarding entries of the optimal route. If the primary link fails, the routing device quickly switches traffic to the backup link. The switchover does not depend on route convergence and can be performed within sub-seconds, greatly reducing service interruption time. For BGP labeled routes, FRR is supported only on the ingress and transit nodes.

Implementation Procedure

If both the ip frr and auto-frr commands are configured, the auto-frr command takes precedence over the ip frr command.

Precautions

Using both BGP Auto FRR and BFD is recommended. They can rapidly detect a link fault and switch traffic to a backup link if a fault occurs.