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4.2.5 (Optional) Configuring VRRP Time Parameters
The preemption delay and the interval at which the master router sends a gratuitous ARP packet
can be set for a VRRP backup group. These parameters help VRRP links to work stably and
optimize the performance of a VRRP backup group.
Context
The following time parameters can be set to optimize the functions of a VRRP backup group:
l
Preemption delay: If a master router fails, a backup router can preempt the Master state
only after a specified delay. A master/backup VRRP switchover is frequently performed
on an unstable network where the BFD or EFM status tracked by a VRRP backup group is
flapping or backup routers are unable to receive VRRP Advertisement packets within a
specified period. This causes network flapping. To prevent this problem, set a preemption
delay. routers in a VRRP backup group will preempt the Master state after the specified
delay.
NOTICE
If the IP address owner recovers, it switches to the Master state immediately without waiting
a specified preemption delay. This process violates the preemption delay setting. Therefore,
in a VRRP backup group, the preemption delay and the IP address owner cannot be
configured together.
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The interval at which a gratuitous ARP packet is sent can be set on the master router as
needed.
Procedure
l
Set the preemption delay for a VRRP backup group.
1.
Run:
system-view
The system view is displayed.
2.
Run:
interface
interface-type
interface-number
The interface view is displayed.
3.
Run:
vrrp vrid
virtual-router-id
preempt-mode
timer
delay
delay-value
The preemption delay is set for routers in a VRRP backup group.
The default delay is 0s, meaning immediate preemption. In a VRRP backup group
working in immediate preemption mode, a backup router can immediately preempt
the Master state when its priority is higher than the master router. After preemption
is complete, the master router becomes a backup router.
The
vrrp vrid
virtual-router-id
preempt-mode
disable
command is used to set the
non-preemption mode for routers in the VRRP backup group. In a VRRP backup group
HUAWEI NetEngine80E/40E Router
Configuration Guide - Reliability
4 VRRP Configuration
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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