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BFD
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42. BFD
42.1
Introduction to BFD
BFD (Bidirectional Forwarding Detection) provides a detection mechanism to quickly
detect and monitor the connectivity of links in networks. To improve network performance,
between protocol neighbors must quickly detect communication failures to restore
communication through backup paths as soon as possible.
BFD
provides
a
general-purpose,
standard,
medium-independent
and
protocol-independent fast failure detection mechanism. It can uniformly and quickly detect
the failures of the bidirectional forwarding paths between two network devices for
superstratum protocols, such as routing protocols and Multiprotocol Label Switching
(MPLS). BFD establishes session between two network devices to monitor their
bidirectional forwarding paths to serve for superstratum protocols. However, there is no
discovery mechanism for BFD, it is notified by superstratum protocol to establish sessions.
After a session is established, if no BFD control packet is received from the peer within
detection time, it notifies the failure to superstratum protocol which will take appropriate
measures.
42.2
BFD Configuration Task List
1. Configure BFD basic function
2. Configure BFD for RIP (ng)
3. Configure BFD for static route (IPv6)
4. Configure BFD for VRRP (v3)
1. Configure BFD basic function
Command
Explanation
Global Mode
bfd mode{active | passive}
no bfd mode
Configure the mode before
establishing BFD session,
the default is active mode.
No command restores active
mode.
bfd authentication key <
1-255
> text <
WORD>
no bfd authentication key <
1-255>
Configure
key
and
authentication
character