BFD Session Configuration Where Next Hop is a LAG Interface
When the TX port, or next hop, on which a BFD session is to be configured is a LAG member, the BFD session is configured on one of the member ports of the LAG. Applications are notified about the session based on the session status of this member port alone. If the BFD session on this member port goes down, applications are then notified to act on the link failure even though the LAG remains operational. To postpone this event, the holdover timer can be set to a higher time interval during which the session can come back up due to the successful movement to another operational LAG member port. Refer to Holdover Timer, and to the RUCKUS FastIron Command Reference, for more information. With this configuration, if a micro-BFD session down notification for a LAG member port is received, the multihop BFD session is moved to the next available LAG member port.
For more information on micro-BFD refer to Micro BFD.
The following figure shows a multihop BFD session running over a LAG interface with no underlying single-hop micro-BFD session also running on the LAG interface. With such a configuration, when a multihop session down notification or a LAG member port down notification is received, the multihop BFD session is moved to the next available LAG member port.
