BFD Operational Modes

BFD Asynchronous mode is not administratively enabled or disabled. BFD operates in Asynchronous mode any time Demand mode is disabled. When Demand mode is configured, BFD remains in Asynchronous mode for a specified length of time prior to enabling Demand mode on the BFD probe session. Once Demand mode is enabled on the BFD session probe, Control packets are no longer sent by the neighbor, A BFD probe session operating in Demand mode is dependent upon Echo packets for verification of the liveliness of a neighbor. Demand mode is disabled by default.

Use the demand-mode command, in BFD probe configuration command mode, to enable Demand mode for this BFD probe session after the specified interval in seconds.

This example shows how to enable Demand mode for BFD session bfdProbe1 after the sessions has been up for 30 seconds:

System(rw)->configure
System(rw-config)->probe bfdProbe1 bfd
System(su-config-probe-bfd)->demand-mode 30
System(su-config-probe-bfd)->