BFD can provide link failure detection featuring light load and high speed (within milliseconds). With dynamic BFD, routing protocols can dynamically trigger the establishment of BFD sessions.
IS-IS detects neighbor status by exchanging hello packets. For networks that require fast convergence and zero packet loss, IS-IS is unreliable to detect link faults. To address this issue, configure BFD for IS-IS.
BFD includes static BFD and dynamic BFD. In dynamic BFD, BFD session establishment is triggered by routing protocols. Dynamic BFD minimizes configuration errors caused by manual operations in static BFD and is easy to configure. Therefore, dynamic BFD is applicable to networks on which all devices require BFD. Dynamic BFD helps detect link faults rapidly and implement fast route convergence.