Configuring Bidirectional Forwarding Detection (BFD) on Interfaces (S-, K-Series)

BFD is used to detect a communications failure with an OSPF forwarding plane next-hop. BFD detects failures in under one second. BFD augments the OSPF Hello mechanism. The OSPF Hello interval defaults to 10 seconds. With high speed data rates, a failure requiring multiple seconds to detect can result in significant data loss. The OSPF implementation of the BFD protocol uses the following non-configurable parameters:

  • Transmit Interval – The period of time between the transmission of BFD control packets, set for 100ms.
  • Receive Interval – The period of time between received BFD control packets, set for 100ms.
  • Detection Multiplier – The Number of consecutive control packets that can be missed before the BFD session transitions to down, set to 3.

Use the bfd all-intfs-on command in OSPF router configuration mode to enable BFD on all OSPF interfaces.