Field DescriptionDetection Multiplier The number of packets that must be missed in order to declare a session down.Length The entire length of the BFD packet.My Discriminator A random number generated by the local system to identify the session.Your Discriminator A random number generated by the remote system to identify the session. Discriminator values are necessary toidentify the session to which a control packet belongs because there can be many sessions running on a singleinterface.Desired Min TXIntervalThe minimum rate at which the local system would like to send control packets to the remote system.Required Min RXIntervalThe minimum rate at which the local system would like to receive control packets from the remote system.Required Min EchoRXThe minimum rate at which the local system would like to receive echo packets.NOTE: Dell Networking OS does not currently support the echo function.Authentication Type,AuthenticationLength,Authentication DataAn optional method for authenticating control packets.NOTE: Dell Networking OS does not currently support the BFD authentication function.Two important parameters are calculated using the values contained in the control packet.Transmit Interval Transmit interval is the agreed-upon rate at which a system sends control packets. Each system has its owntransmit interval, which is the greater of the last received remote Desired TX Interval and the local Required MinRX Interval.Detection time Detection time is the amount of time that a system does not receive a control packet, after which the systemdetermines that the session has failed. Each system has its own detection time.• In Asynchronous mode: Detection time is the remote Detection Multiplier multiplied by greater of the remoteDesired TX Interval and the local Required Min RX Interval.• In Demand mode: Detection time is the local Detection Multiplier multiplied by the greater of the local DesiredMin TX and the remote Required Min RX Interval.BFD SessionsBFD must be enabled on both sides of a link in order to establish a session.The two participating systems can assume either of two roles:Active The active system initiates the BFD session. Both systems can be active for the same session.Passive The passive system does not initiate a session. It only responds to a request for session initialization from the activesystem.A BFD session has two modes:Asynchronous mode In Asynchronous mode, both systems send periodic control messages at an agreed upon interval to indicate thattheir session status is Up.’146 Bidirectional Forwarding Detection (BFD)
