Configuring BFD for BGP


[IMPORTANT: ]

IMPORTANT:

If you have enabled GR, use BFD with caution because BFD might detect a failure before the system performs GR, which will result in GR failure. If you have enabled both BFD and GR for BGP, do not disable BFD during a GR process to avoid GR failure.


BGP maintains neighbor relationships based on the keepalive timer and hold timer in seconds. It requires that the hold time must be at least three times the keepalive interval. This mechanism slows down link failure detection. Once a failure occurs on a high-speed link, a large quantity of packets will be dropped before routing convergence completes. BFD for BGP can solve this problem by fast detecting link failures to reduce convergence time.

Before you enable BFD for a BGP peer or peer group, you must establish a BGP session between the local router and the peer or peer group.

For more information about BFD, see High Availability Configuration Guide.

To enable BFD for a BGP peer (IPv4 unicast/multicast address family):

Step

Command

Remarks

1. Enter system view.

system-view

N/A

2. Enter BGP instance view or BGP-VPN instance view.

  • Enter BGP instance view:bgp as-number [ instance instance-name ]

  • Enter BGP-VPN instance view:

    1. bgp as-number [ instance instance-name ]

    2. ip vpn-instance vpn-instance-name

N/A

3. Enable BFD to detect the link to the specified BGP peer or peer group.

peer { group-name | ipv4-address [ mask-length ] } bfd [ multi-hop | single-hop ]

By default, BFD is disabled.

To enable BFD for a BGP peer (IPv6 unicast/multicast address family):

Step

Command

Remarks

1. Enter system view.

system-view

N/A

2. Enter BGP instance view or BGP-VPN instance view.

  • Enter BGP instance view:bgp as-number [ instance instance-name ]

  • Enter BGP-VPN instance view:

    1. bgp as-number [ instance instance-name ]

    2. ip vpn-instance vpn-instance-name

N/A

3. Enable BFD to detect the link to the specified IPv6 BGP peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } bfd [ multi-hop | single-hop ]

By default, BFD is disabled.