Huawei AR530 Series Configuration Manual page 184

Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Reliability
Table 6-6 Applicable scenarios of VRRP time parameters
Parameter
Interval at which
VRRP
Advertisement
packets are sent
Preemption delay
Timeout interval at
which gratuitous
ARP packets are
sent by the master
Delay before a
VRRP group
recovers
Procedure
l
Issue 01 (2014-11-30)
Applicable Scenario
The master in a VRRP group sends VRRP Advertisement packets to
backups at intervals to notify that it is working properly. After the
Master_Down_Interval timer expires, the backup with the highest
priority switches to the master if it does not receive VRRP
Advertisement packets.
Heavy network traffic or time differences on different devices may
result in the status change of the backups due to timeout of VRRP
Advertisement packets. When packets from the original master reach
the new master, the status of the new master changes. You can increase
the interval to solve this problem.
On an unstable network, if the BFD session status monitored by a VRRP
group flaps frequently or the backups cannot receive VRRP
Advertisement packets within a specified period, an active/standby
switchover is frequently performed, which causes network flapping.
You can adjust the preemption delay of the master in the VRRP group
so that the backup with the highest priority switches to the master after
the delay. This prevents frequent change of the VRRP group status.
To ensure that MAC address entries on the downstream switch are
correct, the master in a VRRP group periodically sends gratuitous ARP
packets to update MAC address entries on the downstream switch.
NOTE
Do not configure special MAC addresses such as the system MAC address and
VRRP virtual MAC address as blackhole MAC addresses on the backup to
prevent VRRP flapping.
On an unstable network, frequent flapping of the BFD session status or
interface status monitored by a VRRP group may result in frequent
switching of the VRRP group status. After the delay is set, the VRRP
group does not immediately respond to an interface or BFD session Up
event. Instead, the VRRP group processes this event after the delay.
This prevents frequent switching of the VRRP group status.
Set the interval at which VRRP Advertisement packets are sent.
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 timer advertise advertise-interval
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6 VRRP Configuration
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