Users Guide

CONFIG-ROUTERBGP mode
neighbor {ip-address | peer-group name} remote-as as-number
4. Enable the BGP neighbor.
CONFIG-ROUTERBGP mode
neighbor {ip-address | peer-group-name} no shutdown
5. Configure parameters for a BFD session established with all neighbors discovered by BGP. OR Establish a BFD session with a specified
BGP neighbor or peer group using the default BFD session parameters.
CONFIG-ROUTERBGP mode
bfd all-neighbors [interval millisecs min_rx millisecs multiplier value role {active |
passive}]
OR
neighbor {ip-address | peer-group-name} bfd
NOTES:
• When you establish a BFD session with a specified BGP neighbor or peer group using the neighbor bfd command, the default
BFD session parameters are used (interval: 100 milliseconds, min_rx: 100 milliseconds, multiplier: 3 packets, and role: active).
• When you explicitly enable or disable a BGP neighbor for a BFD session with the neighbor bfd or neighbor bfd disable
commands, the neighbor does not inherit the BFD enable/disable values configured with the bfd all-neighbors command or
configured for the peer group to which the neighbor belongs. Also, the neighbor only inherits the global timer values configured
with the bfd all-neighbors command (interval, min_rx, and multiplier).
6. Repeat Steps 1 to 5 on each BGP peer participating in a BFD session.
Disabling BFD for BGP
You can disable BFD for BGP.
To disable a BFD for BGP session with a specified neighbor, use the first command. To remove the disabled state of a BFD for BGP
session with a specified neighbor, use the second command.
The BGP link with the neighbor returns to normal operation and uses the BFD session parameters globally configured with the bfd all-
neighbors command or configured for the peer group to which the neighbor belongs.
• Disable a BFD for BGP session with a specified neighbor.
ROUTER BGP mode
neighbor {ip-address | peer-group-name} bfd disable
• Remove the disabled state of a BFD for BGP session with a specified neighbor.
ROUTER BGP mode
no neighbor {ip-address | peer-group-name} bfd disable
Use BFD in a BGP Peer Group
You can establish a BFD session for the members of a peer group (the neighbor peer-group-name bfd command in ROUTER
BGP configuration mode).
Members of the peer group may have BFD:
• Explicitly enabled (the neighbor ip-address bfd command)
• Explicitly disabled (the neighbor ip-address bfd disable command)
• Inherited (neither explicitly enabled or disabled) according to the current BFD configuration of the peer group. For information about
BGP peer groups, refer to Configure Peer Groups.
If you explicitly enable (or disable) a BGP neighbor for BFD that belongs to a peer group:
• The neighbor does not inherit the BFD enable/disable values configured with the bfd all-neighbors command or configured for
the peer group to which the neighbor belongs.
• The neighbor inherits only the global timer values that are configured with the bfd all-neighbors command (interval, min_rx,
and multiplier).
If you explicitly enable (or disable) a peer group for BFD that has no BFD parameters configured (for example, advertisement interval)
using the neighbor peer-group-name bfd command, the peer group inherits any BFD settings configured with the bfd all-
neighbors command.
Bidirectional Forwarding Detection (BFD)
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