Users Guide

Establishing Sessions with OSPFv3 Neighbors
You can establish BFD sessions with all OSPFv3 neighbors at once or with all neighbors out of a specific interface. Sessions are only
established when the OSPFv3 adjacency is in the Full state.
To establish BFD with all OSPFv3 neighbors or with OSPFv3 neighbors on a single interface, use the following commands.
• Establish sessions with all OSPFv3 neighbors.
ROUTER-OSPFv3 mode
bfd all-neighbors
• Establish sessions with OSPFv3 neighbors on a single interface.
INTERFACE mode
ipv6 ospf bfd all-neighbors
To view the established sessions, use the show bfd neighbors command.
Changing OSPF Session Parameters
Configure BFD sessions with default intervals and a default role.
The parameters that you can configure are: desired tx interval, required min rx interval, detection multiplier,
and system role. Configure these parameters for all OSPF sessions or all OSPF sessions on a particular interface. If you change a
parameter globally, the change affects all OSPF neighbors sessions. If you change a parameter at the interface level, the change affects all
OSPF sessions on that interface.
To change parameters for all OSPF sessions or for OSPF sessions on a single interface, use the following commands.
• Change parameters for OSPF sessions.
ROUTER-OSPF mode
bfd all-neighbors interval milliseconds min_rx milliseconds multiplier value role [active |
passive]
• Change parameters for all OSPF sessions on an interface.
INTERFACE mode
ip ospf bfd all-neighbors interval milliseconds min_rx milliseconds multiplier value role
[active | passive]
To view session parameters, use the show bfd neighbors detail command.
Disabling BFD for OSPF
If you disable BFD globally, all sessions are torn down and sessions on the remote system are placed in a Down state.
If you disable BFD on an interface, sessions on the interface are torn down and sessions on the remote system are placed in a Down state.
Disabling BFD does not trigger a change in BFD clients; a final Admin Down packet is sent before the session is terminated.
To disable BFD sessions, use the following commands.
• Disable BFD sessions with all OSPF neighbors.
ROUTER-OSPF mode
no bfd all-neighbors
• Disable BFD sessions with all OSPF neighbors on an interface.
INTERFACE mode
ip ospf bfd all-neighbors disable
Configure BFD for IS-IS
When using BFD with IS-IS, the IS-IS protocol registers with the BFD manager on the RPM. BFD sessions are then established with all
neighboring interfaces participating in IS-IS. If a neighboring interface fails, the BFD agent on the line card notifies the BFD manager,
which in turn notifies the IS-IS protocol that a link state change occurred.
Configuring BFD for IS-IS is a two-step process:
1. Enable BFD globally.
2. Establish sessions for all or particular IS-IS neighbors.
Bidirectional Forwarding Detection (BFD)
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