Dell EMC Configuration Guide for the S3100 Series 9.14.2.4

Example configuration of BGP fast fall-over

DellEMC# configure terminal
DellEMC(conf)# router bgp 400
DellEMC(conf-router_bgp)# neighbor 10.10.10.1 remote-as 500
DellEMC(conf-router_bgp)# neighbor 10.10.10.1 fall-over
DellEMC(conf-router_bgp)# exit
DellEMC(conf-router_bgp)#

To verify that you enabled fast fall-over on a particular BGP neighbor, use the show ip bgp neighbors command. Because fast fall-over is disabled by default, it appears only if it has been enabled (shown in bold).

DellEMC#show ip bgp neighbors

BGP neighbor is 10.10.10.1, remote AS 500, internal link
  Member of peer-group test for session parameters
  BGP version 4, remote router ID 30.30.30.5
  BGP state ESTABLISHED, in this state for 00:19:15
  Last read 00:00:15, last write 00:00:06
  Hold time is 180, keepalive interval is 60 seconds
  Received 52 messages, 0 notifications, 0 in queue
  Sent 45 messages, 5 notifications, 0 in queue
  Received 6 updates, Sent 0 updates
  Route refresh request: received 0, sent 0
  Minimum time between advertisement runs is 5 seconds
  Minimum time before advertisements start is 0 seconds
  
  Capabilities received from neighbor for IPv4 Unicast :
    MULTIPROTO_EXT(1)
    ROUTE_REFRESH(2)
    CISCO_ROUTE_REFRESH(128)

  Capabilities advertised to neighbor for IPv4 Unicast :
    MULTIPROTO_EXT(1)
    ROUTE_REFRESH(2)
    CISCO_ROUTE_REFRESH(128)

fall-over enabled

Update source set to Loopback 0

Peer active in peer-group outbound optimization

For address family: IPv4 Unicast
BGP table version 52, neighbor version 52
4 accepted prefixes consume 16 bytes
Prefix advertised 0, denied 0, withdrawn 0

Connections established 6; dropped 5
Last reset 00:19:37, due to Reset by peer

Notification History
  'Connection Reset' Sent : 5 Recv: 0

Local host: 20.20.20.2, Local port: 65519
Foreign host: 10.10.10.1, Foreign port: 179

DellEMC#

To verify that fast fall-over is enabled on a peer-group, use the show ip bgp peer-group command (shown in bold).

DellEMC#show ip bgp peer-group

Peer-group test
  fall-over enabled
  BGP version 4
  Minimum time between advertisement runs is 5 seconds

  For address family: IPv4 Unicast
  BGP neighbor is test
  Number of peers in this group 1
  Peer-group members (* - outbound optimized):
    10.10.10.1*

DellEMC#

router bgp 400
  neighbor test peer-group
  neighbor test fall-over
  neighbor test no shutdown
  neighbor 10.10.10.1 remote-as 500
  neighbor 10.10.10.1 fall-over
  neighbor 10.10.10.1 update-source Loopback 0
  neighbor 10.10.10.1 no shutdown
DellEMC#