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NOTE
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The BFD session does not report the BFD status to the bound interface immediately after the
commit
command is executed because the BFD session may not be set up or not Up. This prevents the
BFD session from reporting an incorrect state to the interface. When the BFD status changes, the BFD
session reports the BFD status to the interface to trigger the interface status change.
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If the BFD session must be synchronized to an interface immediately, ensure that the BFD
configurations on the two routers are the same and run the
shutdown
and
undo shutdown
commands
on the BFD session. When the
undo shutdown
command is executed for a BFD session, a BFD session
detection timer is started. If the BFD session becomes Up through negotiation before the timer times
out, the BFD session notifies an interface of the Up state. Otherwise, the BFD session considers the
link faulty and notifies the interface of the Down state. The status of a BFD session and the status of
an interface can be synchronized in real time.
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If the
process-interface-status
command is saved in the configuration file, the BFD session for which
the
process-interface-status
command is run notifies an interface that the BFD session becomes Down
when the router is restarted, in view of the initial status of the interface being Down.
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Before the BFD status is associated with the interface status, the BFD configurations on two routers
must be correct and matched. If the BFD status on the local interface is Down, check whether the BFD
configuration on the remote end is correct and the BFD session is shut down.
----End
Example
Run the
display bfd session
all
verbose
command. The value of the
Proc interface status
field
is
Enable(Sub-If)
, indicating that the BFD session
aa
has been associated with the main interface
and sub-interface.
<Huawei>
display bfd session all verbose
--------------------------------------------------------------------------------
Session MIndex : 64 (One Hop) State : Up Name : aa
--------------------------------------------------------------------------------
Local Discriminator : 1 Remote Discriminator : 2
Session Detect Mode : Asynchronous Mode Without Echo Function
BFD Bind Type : Interface(GigabitEthernet1/0/0)
Bind Session Type : Static
Bind Peer IP Address :
224.0.0.184
NextHop Ip Address :
224.0.0.184
Bind Interface : GigabitEthernet1/0/0
FSM Board Id : 0 TOS-EXP : 7
Min Tx Interval (ms) : 1000 Min Rx Interval (ms) : 1000
Actual Tx Interval (ms): 1000 Actual Rx Interval (ms): 1000
Local Detect Multi : 3 Detect Interval (ms) : 3000
Echo Passive : Disable Acl Number : -
Destination Port : 3784 TTL : 255
Proc Interface Status :
Enable(Sub-If)
WTR Interval (ms) : -
Active Multi : 3
Last Local Diagnostic : Control Detection Time Expired
Bind Application : No Application Bind
Session TX TmrID : - Session Detect TmrID : -
Session Init TmrID : - Session WTR TmrID : -
Session Echo Tx TmrID : -
PDT Index : FSM-0 | RCV-0 | IF-0 | TOKEN-0
Session Description : -
--------------------------------------------------------------------------------
Total UP/DOWN Session Number : 1/0
Huawei AR2200-S Series Enterprise Routers
Configuration Guide - Reliability
3 BFD Configuration
Issue 01 (2012-01-06)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
169