Bidirectional Forwarding Detection (BFD) for the Border Gateway Protocol (BGP)

Bidirectional Forwarding Detection (BFD) protection of Border Gateway Protocol (BGP) peering sessions allows for the rapid detection of link failures such that peering sessions can be taken out of the "established" state within fractions of a second. This allows the protocol to select an alternate path (if available) to a destination immediately after the link failure, rather than waiting until the BGP hold timer expires (180 seconds by default). This feature applies to both IPv4 and IPv6 peering sessions. Both IPv6 global and link local peering sessions are supported.

Supported Platforms

Summit X460-G2, X670-G2, X770 series switches, with Core License or above.

Limitations

  • The BFD setting can be applied on a per-peer basis, but the ability to set BFD on a peer-group or address-family basis is not currently supported.
  • The BGP peer must be in the disabled admin state to modify its BFD setting.
  • While BFD can be enabled on any BGP peering session, protection is only provided for directly connected EBGP peering sessions.

New CLI Commands

configure bgp {neighbor [all|remoteaddr]} {bfd [on | off]}

Changed CLI Commands

The show bgp neighbor command now shows BFD information (shown in bold):

show bgp neighbor 192.168.24.2 
Peer Description    : 
EBGP Peer           : 192.168.24.2      AS                  : 300   
Enabled             : Yes               OperStatus          : Up
Weight              : 1                 Shutdown-Priority   : 1024
ConnectRetry        : 120               MinAsOrig           : 30
HoldTimeCfg         : 180               KeepaliveCfg        : 60
Source Interface    : Not configured    RRClient            : No
EBGP-Multihop       : No                Remove Private AS   : No 
BFD                 : Off               BFD Status          : Inactive