VRRP slow switching from backup to master on S6730

Issue Description

Customer encounters an issue with VRRP switchover on two 2 x S6730-H switches configured with VRRP. After VRRP master switch restarts, VRRP backup switch becomes the master. The switchover should occur in seconds, but it takes up to 5 minutes.

Handling Process

1.      Check the status of vrrp from the output of display vrrp

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Normally, after the VRRP master restarts, the VRRP hello on the backup will time out and then become the master.

2.      Check if all the interfaces of the corresponding VLAN on the backup device have become DOWN during the test. In this way, VRRP will become the Initialize state, and the corresponding vlanif interface must be UP for VRRP switching.
From the log the device restarted on 2 boards in turn at around 17:30
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3.      Check the smooth-switching function
In this VRRP hello, it contains a new VRRP timer which is configured in the command “vrrp smooth-switching timer” which by default, it is 100s  and VRRP backup device will learn this new timer and change the VRRP expired internal to 100s. If 3 hello packets can’t receive anymore, then backup will become master, since now the expired internal already updated to 100s, so 3*hello timer will extend to 300s. This is why the switchover takes approximatively 5 minutes.

Root Cause

This issue is caused by the smooth-switching function for VRRP, when you first power off the main board on the VRPP master, it will trigger the switchover and send VRRP hello to backup.

Solution

Set the interval contained in VRRP Advertisement packets during VRRP smooth switching to 1 second.

<HUAWEI> system-view

[HUAWEI] vrrp smooth-switching timer 1