Reference Guide

8
Bidirectional Forwarding Detection (BFD)
Bidirectional forwarding detection (BFD) is a detection protocol that provides fast forwarding path failure detection.
The Dell Networking operating software (FTOS) implementation is based on the standards specified in the IETF Draft
draft-ietf-bfd-base-03.
BFD is supported on the S4820T platform.
bfd all-neighbors
Enable BFD sessions with all neighbors discovered by Layer 3 protocols virtual router redundancy protocol (VRRP),
intermediate system to intermediate system (IS-IS), open shortest path first (OSPF), OSPFv3, or border gateway protocol
(BGP) on router interfaces, and (optionally) reconfigure the default timer values.
S4820T
Syntax
[vrrp] bfd all-neighbors [interval interval min_rx min_rx
multiplier value role {active | passive}]
Parameters
vrrp Enter the keyword vrrp in INTERFACE mode to enable BFD for
VRRP.
interval
milliseconds
(OPTIONAL) Enter the keyword interval to specify non-default
BFD session parameters beginning with the transmission interval. The
range is from 50 to 1000. The default is
100.
min_rx
milliseconds
Enter the keyword min_rx to specify the minimum rate at which the
local system would like to receive control packets from the remote
system. The range is from 50 to 100. The default is 100.
multiplier value Enter the keyword multiplier to specify the number of packets
that must be missed in order to declare a session down. The range is
from 3 to 50. The default is
3.
role [active |
passive]
Enter the role that the local system assumes:
• 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
active system.
The default is active.
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