Configuring BGP Auto FRR

BGP Auto FRR, a protection measure against link faults, applies to the network topology with both primary and backup links. It can be configured for services that are quite sensitive to the packet loss and delay.

Usage Scenario

As networks evolve continuously, voice, on-line video, and financial services raise increasingly high requirements for real-time performance. Usually, primary and backup links are deployed on a network to ensure the stability of these services. In a traditional forwarding mode, the router selects a route out of several routes that are bound for the same destination network as the optimal route and delivers the route to the FIB table to guide data forwarding. If the optimal route fails, the router has to wait for route convergence to be completed before reselecting an optimal route. During this period, services are interrupted. After the router delivers the reselected optimal route to the FIB table, services are restored. Service interruption in this mode lasts a long time, which cannot meet services' 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 router quickly switches traffic to the backup link. The switchover does not depend on route convergence. Therefore, the service interruption time is very short, reaching the sub-second level.

Pre-configuration Tasks

Before configuring BGP Auto FRR, complete the following task:

Procedure

  1. Run system-view

    The system view is displayed.

  2. Run bgp as-number

    The BGP view is displayed.

  3. Run ipv4-family unicast

    The BGP IPv4 unicast address family view is displayed.

  4. Run auto-frr

    BGP Auto FRR for unicast routes is enabled.

  5. (Optional) Run route-select delay delay-value

    A delay for selecting a route to the intermediate device on the primary path is configured. After the primary path recovers, an appropriate delay ensures that traffic switches back to the primary path after the intermediate device completes refreshing forwarding entries.

  6. Run commit

    The configuration is committed.

Checking the Configurations

After configuring BGP Auto FRR, you can run the following commands to check the previous configuration.

  • Run the display bgp routing-table [ network [ { mask | mask-length } [ longer-prefixes ] ] ] command to check information in a BGP routing table.
  • Run the display ip routing-table [ ip-address [ mask | mask-length ] [ longer-match ] ] verbose command to check backup forwarding entries in an IP routing table.
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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