Micro-BFD

Micro-BFD sessions are BFD sessions running on member links of the LAG. Micro-BFD sessions provide BFD with the ability to verify link continuity for every LAG member link. Micro-BFD helps to guarantee the detection of physical member link failures, as well as the overall LAG interface failure. A single micro-BFD session runs on each member link of the LAG for every enabled address family.

Each micro-BFD session uses its own unique local discriminator values, maintains its own set of state variables, and has its own state machine.

Note: The timer values remain the same for all micro-BFD sessions for a LAG interface.

Micro-BFD is capable of detecting the overall LAG interface failure and performs the following tasks:

  • If a micro-BFD session state for all LAG member links is down, the BFD state of the overall LAG interface is marked as down and all applications and protocols participating in the BFD session are notified.
  • If a micro-BFD session comes up, the BFD state of the overall LAG interface is marked as up and all applications and protocols participating in the BFD session are notified.

BFD session parameters, configured at the global level for a protocol or application, apply for micro-BFD sessions.

Note: A maximum number of 100 micro-BFD sessions are supported.
Note: Micro-BFD and Multi-hop-BFD cannot be enabled at the same time. Enabling micro-BFD automatically disables multihop for BFD. Switching from one mode to another requires a system reboot.

To configure micro-BFD, all LAG member links must be directly connected between two session endpoints, as illustrated in the following figure.

Micro-BFD Session

For detailed configuration examples that include micro-BFD configurations, refer to BFD Configuration Examples.

In this section:

  1. Enabling Micro-BFD Globally
    Micro-BFD can be enabled globally. The following task enables micro-BFD globally.
  2. Configuring Micro-BFD for the Member Links of a LAG Interface
    Micro-BFD can be enabled on each member link of a LAG interface so that link continuity for every LAG member link can be verified. The following task configures a static LAG, adds ports to the static LAG, configures a LAG virtual interface for the static LAG, and enables micro-BFD for each member link of the LAG interface.
  3. BFD Configuration on One LAG Member Port
Parent topic: BFD